Bitrate efficient transport through distributed antenna systems

ABSTRACT

An antenna unit includes a first lower layer processor configured to receive a first lower layer signal from a device and to convert the first lower layer signal into first higher layer data units; a higher layer processor configured to convert the first higher layer data units into second higher layer data units; a second lower layer processor configured to generate a second lower layer signal from the second higher layer data units; and a radio frequency conversion module configured to convert the second lower layer signal into radio frequency signals for communication using an antenna; wherein communication between the device and the antenna unit using the first lower layer signal having the first higher layer data units has a lower data rate than would communication between the device and the antenna unit using the second lower layer signal having the second higher layer data units.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/626,689 (hereafter the '689 application)entitled “BITRATE EFFICIENT TRANSPORT THROUGH DISTRIBUTED ANTENNASYSTEMS”, filed on Jun. 19, 2017 which is a continuation application ofU.S. patent application Ser. No. 14/737,230 (hereafter the '230application) entitled “BITRATE EFFICIENT TRANSPORT THROUGH DISTRIBUTEDANTENNA SYSTEMS”, filed on Jun. 11, 2015 which claims the benefit ofU.S. Provisional Patent Application Ser. No. 62/010,938 filed on Jun.11, 2014, all of which are hereby incorporated herein by reference.

This application is related to the following co-pending United Statespatent applications, which are hereby incorporated herein by reference:

U.S. patent application Ser. No. 14/737,179 entitled “BIT EFFICIENTTRANSPORT THROUGH DISTRIBUTED ANTENNA SYSTEMS” filed on Jun. 11, 2015(issued in U.S. Pat. No. 9,596,322);

U.S. patent application Ser. No. 09/649,159 entitled “METHODS ANDSYSTEMS FOR COMMUNICATING IN A CELLULAR NETWORK” filed on Aug. 28, 2000(issued in U.S. Pat. No. 6,836,660) and which is referred to herein asthe '159 application; and

U.S. patent application Ser. No. 12/372,319 entitled “DISTRIBUTEDANTENNA SYSTEM USING GIGABIT ETHERNET PHYSICAL LAYER DEVICE” filed onFeb. 17, 2009 (published as U.S. 2010/0208777) and which is referred toherein as the '319 application.

BACKGROUND

Distributed Antenna Systems (DAS) are used to distribute wireless signalcoverage into buildings or other substantially closed environments. Forexample, a DAS may distribute antennas within a building. The antennasare typically connected to a radio frequency (RF) signal source, such asa service provider. Various methods of transporting the RF signal fromthe RF signal source to the antenna have been implemented in the art.

SUMMARY

An antenna unit includes a transport Layer 1 processor configured toreceive a downlink transport Layer 1 data stream from an upstream deviceand to convert the downlink transport Layer 1 data stream into downlinktransport Layer 2 protocol data units in a downlink transport Layer 2; aLayer 2 processor configured to convert the downlink transport Layer 2protocol data units in the downlink transport Layer 2 into downlinkradio access technology Layer 2 protocol data units in a radio accesstechnology Layer 2; a radio access technology Layer 1 processorconfigured to generate a downlink radio access technology Layer 1 signalfrom the downlink radio access technology Layer 2 protocol data units inthe radio access technology Layer 2; and a radio frequency conversionmodule configured to convert the downlink radio access technology Layer1 signal into radio frequency signals for communication using anantenna.

DRAWINGS

Understanding that the drawings depict only exemplary embodiments andare not therefore to be considered limiting in scope, the exemplaryembodiments will be described with additional specificity and detailthrough the use of the accompanying drawings, in which:

FIGS. 1A-1D are block diagrams of exemplary embodiments of distributedantenna systems;

FIGS. 2A-2B are block diagrams of exemplary embodiments of host unitsused in distributed antenna systems, such as the exemplary distributedantenna systems in FIGS. 1A-1B;

FIGS. 3A-3J are block diagrams of exemplary embodiments of host networkinterfaces used in host units of distributed antenna systems, such asthe exemplary distributed antenna hosts in FIGS. 2A-2B;

FIGS. 4A-4B are block diagrams of exemplary embodiments of antenna unitsused in distributed antenna systems, such as the exemplary distributedantenna systems in FIGS. 1A-1D;

FIGS. 5A-5D are block diagrams of exemplary embodiments of RF conversionmodules used in antenna units of distributed antenna systems, such asexemplary antenna units in FIGS. 4A-4B;

FIG. 6 is a block diagram of an exemplary embodiment of a radio access(RAN) network interface used in distributed antenna systems, such as theexemplary distributed antenna systems in FIGS. 1A-1D.

FIG. 7 is a flow diagram illustrating an exemplary embodiment of amethod for efficiently transporting wireless network information througha distributed antenna system.

FIG. 8 is a flow diagram illustrating another exemplary embodiment of amethod for efficiently transporting wireless network information througha distributed antenna system.

FIG. 9 is a representation of an exemplary Layer 1 (L1)/Layer 2 (L2)protocol stack for a radio access network (RAN).

FIGS. 10A-10B are block diagrams showing interaction in an exemplarysystem of various levels of a protocol stack, such as the protocol stackshown in FIG. 9.

In accordance with common practice, the various described features arenot drawn to scale but are drawn to emphasize specific features relevantto the exemplary embodiments. Like reference numbers and designations inthe various drawings indicate like elements.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration specific illustrative embodiments. However, it is tobe understood that other embodiments may be utilized and that logical,mechanical, and electrical changes may be made. Furthermore, the methodpresented in the drawing figures and the specification is not to beconstrued as limiting the order in which the individual steps may beperformed. The following detailed description is, therefore, not to betaken in a limiting sense.

The embodiments described below describe a distributed antenna system(DAS) and components within the distributed antenna system (DAS). Thedistributed antenna system is connected to at least one radio accessnetwork (RAN) through at least one radio access network (RAN) interface.In exemplary embodiments, the distributed antenna system includes adistributed antenna system host that interfaces with the at least oneradio access network (RAN) interface and converts wireless networkinformation to a more efficient format for transport across at least onemedium to at least one antenna unit that converts the wireless networkinformation to a radio frequency signal and communicates it wirelesslyusing at least one antenna. More specifically, in some embodimentsmedium access control (MAC) protocol data units (PDUs) are transportedinstead of baseband IQ samples because the wireless network informationis more efficiently transported in MAC PDUs than baseband IQ samples.The ability to transmit the wireless network information in MAC PDUsmore efficiently than the baseband IQ samples enables lower bandwidthmedia to be used, such as Category building cabling such as Category 5,Category 5e, Category 6, Category 6A and Category 7. The ability totransmit the MAC PDUs more efficiently than the baseband IQ samples isessentially a compression technique that enables more data totransmitted over the media. In exemplary embodiments, synchronizationinformation, timing information, power level, signal gain and/or otheradditional overhead is transmitted in addition to the wireless networkinformation. In exemplary embodiments, wireless network information (orcellular network information) is represented in different ways by thedifferent protocol layers. The wireless network information is the same,but it is formatted differently using different headers, control words,error control bits, etc. that are added/removed by the differentprotocol layers throughout the entire system. While described using theterm distributed antenna system (DAS) herein, it is understood that thisdescription also applies to other wireless distribution technologies andnetworks, such as distributed base stations, remote radio heads, and/ora centralized radio access network (CRAN, also known as Cloud-RAN andcoordinated RAN). In exemplary embodiments, the antenna unit is embodiedas a remote radio head. In exemplary embodiments, the radio accessnetwork interface is embodied as a baseband unit in a distributed basestation and/or a centralized radio access network (CRAN).

In exemplary embodiments, radio access technologies may operate usingvarious wireless protocols and in various bands of frequency spectrum.The systems and methodologies described herein apply equally to a numberof radio access technologies (RAT), though it is more beneficial forradio access technologies (RAT) that are substantially less efficientwith bandwidth at one layer than another. For example, the radio accesstechnologies (RAT) may include, but are not limited to, 800 MHz cellularservice, 1.9 GHz Personal Communication Services (PCS), SpecializedMobile Radio (SMR) services, Enhanced Special Mobile Radio (ESMR)services at both 800 MHz and 900 MHz, 1800 MHz and 2100 MHz AdvancedWireless Services (AWS), 700 MHz uC/ABC services, two way pagingservices, video services, Public Safety (PS) services at 450 MHz, 900MHz and 1800 MHz Global System for Mobile Communications (GSM), 2100 MHzUniversal Mobile Telecommunications System (UMTS), WorldwideInteroperability for Microwave Access (WiMAX), 3rd GenerationPartnership Projects (3GPP) Long Term Evolution (LTE), High Speed PacketAccess (HSPA), or other appropriate communication services. The systemdescribed herein are capable of transporting both Single Input SingleOutput (SISO) and Multiple Input Multiple Output (MIMO) services at anyof the frequencies described above. The systems described herein cansupport any combination of SISO and MIMO signals across various bands offrequency spectrum. In some example embodiments, the systems describedherein may provide MIMO streams for WiMAX, LTE, and HSPA services whileonly providing SISO streams for other services. Other combinations ofMIMO and SISO services are used in other embodiments.

Generally, the ability to switch from one layer to another within aparticular protocol may afford more efficient use of bandwidth and canbe applied to various radio access technologies having various layers,including radio link control (RLC) layers, medium access control (MAC)layers, and physical layers. LTE benefits substantially from aconversion from the physical layer to the MAC layer for transportthrough a DAS because the physical layer is much less efficient withbits than the MAC layer.

In exemplary embodiments, the medium access control (MAC) protocol dataunits (PDUs) are recovered by undoing the LTE physical layer processing(or other physical layer processing, such as another radio accesstechnology's physical layer processing) done by the radio access network(RAN) interface (such as an eNodeB) and extracting just the LTE mediaaccess protocol (MAC) protocol data units (PDUs). In exemplaryembodiments, this conversion to MAC PDUs and back essentially acts as atransport compression and transport decompression system.

FIGS. 1A-1D are block diagrams of exemplary embodiments of distributedantenna systems 100. Each of FIGS. 1A-1B illustrates a differentembodiment of a distributed antenna system 100, labeled 100A-100Brespectively.

FIG. 1A is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100A. Distributed antennasystem 100A includes a host unit 102 and at least one antenna unit 104(including antenna unit 104-1 and any quantity of optional antenna units104 through optional antenna unit 104-A) communicatively coupled to thehost unit 102 through at least one digital communication link 106(including digital communication link 106-1 and any quantity of optionaldigital communication links 106 through optional digital communicationlink 106-A). In exemplary embodiments, the at least one antenna unit 104is remotely located from the host unit 102.

The host unit 102 is communicatively coupled to at least one radioaccess network (RAN) interface 108 (including radio access network (RAN)interface 108-1 and any quantity of optional radio access network (RAN)interfaces 108 through optional radio access network (RAN) interface108-B). In the forward path, the host unit 102 is configured to receivewireless network information from each of the at least one radio accessnetwork (RAN) interface 108. As described in more detail below, the hostunit 102 is configured to convert wireless network information from eachof the at least one radio access network (RAN) interface 108 into a moreefficient format (such as to DAS MAC PDUs from baseband IQ pairs) fortransport (either directly or through other components of thedistributed antenna system 100A) to the at least one antenna unit 104across the at least one digital communication link 106.

Similarly in the reverse path, in exemplary embodiments the host unit102 is configured to receive uplink data streams formatted in a moreefficient format (such as DAS MAC PDUs) across a respective digitalcommunication link 106 from at least one antenna unit 104. In exemplaryembodiments, the host unit 102 is further configured to combine multiplereceived uplink data streams formatted in the more efficient format(such as DAS MAC PDUs) into a single aggregate uplink data streamformatted in the more efficient format (such as DAS MAC PDUs). Inexemplary embodiments, the multiple received uplink data streams arecombined using summation (either digital or analog), weighted summation,averaging, multiplexing, etc. The host unit 102 is further configured toconvert the received uplink data stream (or the aggregate uplink datastream) formatted in the more efficient format (such as DAS MAC PDUs) tosignals formatted for the associated radio access network (RAN)interface 108 (such as baseband IQ samples) and further configured tocommunicate the signals formatted for the associated radio accessnetwork (RAN) interface 108 to the associated radio access network (RAN)interface 108.

Each antenna unit 104 is communicatively coupled to the host unit 102across a digital communication link 106. Specifically, antenna unit104-1 is communicatively coupled to the host unit 102 across digitalcommunication link 106-1 and optional antenna unit 104-A iscommunicatively coupled to the host unit 102 across digitalcommunication link 106-A. In exemplary embodiments, some or all of thedigital communication links 106 are wired digital communication links,such as fiber optic cabling, coaxial cabling, twisted pair cabling, etc.In exemplary embodiments, some or all of the digital communication links106 are wireless digital communication links. In exemplary embodiments,a synchronous data stream using Ethernet PHY components is communicatedacross the digital communication links 106, rather than packetized data,such as traditional Internet Protocol (IP) packets. In exemplaryembodiments, the same hardware found in normal packetized InternetProtocol (IP) transport is used, it is just not wrapped into InternetProtocol (IP) packets. Each antenna unit 104 includes components forconverting the wireless network information from the more efficientformat (such as DAS MAC PDUs) for transport across the at least onedigital communication link 106 to radio frequency, for transmissionwirelessly using the at least one antenna 110.

In the forward/downstream path, each antenna unit 104 is configured toconvert at least one wireless network information from the moreefficient format (such as DAS MAC PDUs) to a downlink radio frequency(RF) signal in a radio frequency band for transmission wirelessly usingthe at least one antenna 110. In exemplary embodiments, this may includeprotocol layer processors, converters, and/or translators, digital toanalog converters, and oscillators described in more detail below. Eachantenna unit 104 is further configured to transmit the downlink radiofrequency signal in the radio frequency band to at least one subscriberunit 112 (including subscriber unit 112-1 and any quantity of optionalsubscriber units 112 through optional subscriber unit 112-D) using atleast one antenna 110. In exemplary embodiments, at least one antennaunit 104-1 is configured to transmit one downlink radio frequency signalto one subscriber unit 112-1 using an antenna 110-1 and another radiofrequency signal to another subscriber unit 112-D using another antenna110-C. In exemplary embodiments, other combinations of radio frequencyantennas 110 and other components are used to communicate othercombinations of radio frequency signals in other various radio frequencybands to various subscriber units 112.

Similarly in the reverse/upstream path, in exemplary embodiments eachantenna unit 104 is configured to receive an uplink radio frequency (RF)signal from at least one subscriber unit 112 using at least one antenna110. Each antenna unit 104 is further configured to convert the radiofrequency signals to at least one uplink data stream. Each antenna unit104 is further configured to convert wireless network information fromthe uplink radio frequency signals to a more efficient format (such asDAS MAC PDUs) for transmission across the at least one digitalcommunication link 106 to the host unit 102. In exemplary embodiments,this may include oscillators, digital to analog converters, and protocollayer converters and/or translators described in more detail below.

In exemplary embodiments, a master reference clock is distributedbetween the various components of the distributed antenna system 100A tokeep the various components locked to the same clock. In exemplaryembodiments, the master reference clock is generated based on a signalreceived from the at least one radio access network interface 108-1. Inexemplary embodiments, the master reference clock is generated withinanother component of the distributed antenna system, such as an antennaunit 104.

FIG. 1B is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100B. Distributed antennasystem 100B includes a host unit 102 and at least one antenna unit 104(including antenna unit 104-1 and any quantity of optional antenna units104 through optional antenna unit 104-A). Distributed antenna system100B includes similar components to distributed antenna system 100A andoperates according to similar principles and methods as distributedantenna system 100A described above. The difference between distributedantenna system 100B and distributed antenna system 100A is thatdistributed antenna system 100B includes a distributed switching network114. Distributed switching network 114 couples the host unit 102 withthe at least one antenna unit 104. Distributed switching network 114 mayinclude one or more distributed antenna switches (such as a DASexpansion host and/or an Ethernet switch) or other intermediarycomponents/nodes that functionally distribute downlink signals from thehost unit 102 to the at least one antenna unit 104. Distributedswitching network 114 also functionally distributes uplink signals fromthe at least one antenna unit 104 to the host unit 102. In exemplaryembodiments, the distributed switching network 114 can be controlled bya separate controller or another component of the system. In exemplaryembodiments the switching elements of the distributed switching network114 are controlled either manually or automatically. In exemplaryembodiments, the routes can be pre-determined and static. In otherexemplary embodiments, the routes can dynamically change based on timeof day, load, or other factors.

Each antenna unit 104 is communicatively coupled to the distributedswitching network 114 across a digital communication link 116.Specifically, antenna unit 104-1 is communicatively coupled to thedistributed switching network 114 across digital communication link116-1 and optional antenna unit 104-A is communicatively coupled to thedistributed switching network 114 across digital communication link116-A. In exemplary embodiments, some or all of the digitalcommunication links 116 are wired digital communication links, such asfiber optic cabling, coaxial cabling, twisted pair cabling, etc. Inexemplary embodiments, some or all of the digital communication links116 are wireless digital communication links. In exemplary embodiments,each antenna unit 104 includes components configured for extracting atleast one downlink data stream from an aggregate downlink data streamand components configured for aggregating at least one uplink datastream into an aggregate uplink data stream as well as at least oneradio frequency converter configured to convert between at least onedata stream and at least one radio frequency band and at least oneantenna 110 configured to transmit and receive signals in the at leastone radio frequency band to at least one subscriber unit 112.

FIG. 1C is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100C. Distributed antennasystem 100C includes at least one radio access network interface 108(such as radio access network interface 108-1 and any quantity ofoptional radio access network interfaces 108 through optional radioaccess network interface 108-B) and at least one antenna unit 104(including antenna unit 104-1 and any quantity of optional antenna units104 through optional antenna unit 104-A). Distributed antenna system100C includes some components similar to components of distributedantenna system 100A and operates according to similar principles andmethods as distributed antenna system 100A described above. Thedifference between distributed antenna system 100C and distributedantenna system 100A is that distributed antenna system 100C does notinclude a host unit 102 and the at least one radio access networkinterface 108 transports using the more efficient format directly to theat least one antenna units 104. The at least one radio access networkinterface 108 is communicatively coupled to the at least one antennaunit 104. In exemplary embodiments, a single radio access networkinterface 108 is communicatively coupled to a plurality of antenna units104. In other exemplary embodiments, a plurality of radio access networkinterfaces 108 are communicatively coupled to a single antenna unit 104.

In exemplary embodiments of the forward path, the at least one radioaccess network (RAN) interface 108 is configured to transport (eitherdirectly or through other components of the distributed antenna system100C) the more efficient format (such as DAS MAC PDUs) to the at leastone antenna unit 104 across the at least one digital communication link106, rather than having a host unit 102 convert to the more efficientformat (such as DAS MAC PDUs) from a less efficient format (such asbaseband IQ pairs). Similarly in exemplary embodiments of the reversepath, the at least one radio access network (RAN) interface 108 isconfigured to receive (either directly or through other components ofthe distributed antenna system 100C) the more efficient format (such asDAS MAC PDUs) from the at least one antenna unit 104 across the at leastone digital communication link 106, rather than having a host unitconvert from the more efficient format (such as DAC MAC PDUs) to theless efficient format (such as baseband IQ pairs) in-between the radioaccess network interface 108 and the antenna unit 104.

Each antenna unit 104 is communicatively coupled to the at least oneradio access network interface 108 across a digital communication link106. Specifically, antenna unit 104-1 is communicatively coupled to theradio access network interface 108-1 across digital communication link106-1 and optional antenna unit 104-A is communicatively coupled to theradio access network interface 108-B across digital communication link106-A. In exemplary embodiments, some or all of the digitalcommunication links 106 are wired digital communication links, such asfiber optic cabling, coaxial cabling, twisted pair cabling, etc. Inexemplary embodiments, some or all of the digital communication links106 are wireless digital communication links. Each antenna unit 104includes components for converting, in the forward path, the wirelessnetwork information from the more efficient format (such as DAS MACPDUs) for transport across the at least one digital communication link106 to radio frequency, for transmission wirelessly using the at leastone antenna 110. Each antenna unit 104 also includes components forconverting, in the reverse path, the wireless network information fromradio frequency received wirelessly using the at least one antenna 110to the more efficient format (such as DAS MAC PDUs) for transport acrossthe at least one digital communication link 106 to the at least oneradio access network interface 108.

FIG. 1D is a block diagram of an exemplary embodiment of a distributedantenna system 100, distributed antenna system 100D. Distributed antennasystem 100D includes at least one radio access network interface 108(including radio access network interface 108-1 and any quantity ofoptional radio access network interfaces 108 through optional radioaccess network interfaces 108-B) and at least one antenna unit 104(including antenna unit 104-1 and any quantity of optional antenna units104 through optional antenna unit 104-A). Distributed antenna system100D includes similar components to distributed antenna system 100C andoperates according to similar principles and methods as distributedantenna system 100C described above. The difference between distributedantenna system 100D and distributed antenna system 100C is thatdistributed antenna system 100D includes a distributed switching network114. Distributed switching network 114 couples the at least one radioaccess network interface 108 with the at least one antenna unit 104.Distributed switching network 114 may include one or more distributedantenna switches (such as a DAS expansion unit and/or an Ethernetswitch) or other intermediary components/nodes that functionallydistribute downlink signals from the at least one radio access networkinterface 108 to the at least one antenna unit 104. Distributedswitching network 114 also functionally distributes uplink signals fromthe at least one antenna unit 104 to the at least one radio accessnetwork interface 108. In exemplary embodiments, the distributedswitching network 114 can be controlled by a separate controller oranother component of the system. In exemplary embodiments the switchingelements of the distributed switching network 114 are controlled eithermanually or automatically. In exemplary embodiments, the routes can bepre-determined and static. In other exemplary embodiments, the routescan dynamically change based on time of day, load, or other factors.

Each antenna unit 104 is communicatively coupled to the distributedswitching network 114 across a digital communication link 116.Specifically, antenna unit 104-1 is communicatively coupled to thedistributed switching network 114 across digital communication link116-1 and optional antenna unit 104-A is communicatively coupled to thedistributed switching network 114 across optional digital communicationlink 116-A. In exemplary embodiments, some or all of the digitalcommunication links 116 are wired digital communication links, such asfiber optic cabling, coaxial cabling, twisted pair cabling, etc. Inexemplary embodiments, some or all of the digital communication links116 are wireless digital communication links. In exemplary embodiments,each antenna unit 104 includes components configured for extracting atleast one downlink data stream from an aggregate downlink data streamand components configured for aggregating at least one uplink datastream into an aggregate uplink data stream as well as at least oneradio frequency converter configured to convert between at least onedata stream and at least one radio frequency band and at least oneantenna 110 configured to transmit and receive signals in the at leastone radio frequency band to at least one subscriber unit 112.

FIGS. 2A-2B are block diagrams of exemplary embodiments of host unit102. Each of FIGS. 2A-2B illustrates a different embodiment of a hostunit 102, labeled 102A-102B respectively.

FIG. 2A is a block diagram of an exemplary embodiment of a host unit102, host unit 102A, used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. Exemplaryhost unit 102A includes at least one host network interface 202(including host network interface 202-1 and any quantity of optionalhost network interfaces 202 through optional host network interface202-B), at least one physical layer processor 204 (including physicallayer processor 204-1 and any quantity of optional physical layerprocessors 204 through optional physical layer processor 204-B), adistributed antenna system (DAS) medium access control (MAC) layerprocessor 206, a distributed antenna system (DAS) transport physicallayer processor 208, an optional master host clock unit 210, an optionalprocessor 212, optional memory 214, and an optional power supply 216. Inexemplary embodiments, the at least one physical layer processor 204 isa radio access technology (RAT) physical layer processor, such as an LTEphysical layer processor or another type of RAT physical layerprocessor. In exemplary embodiments, the DAS transport physical layerprocessor 208 is an Ethernet physical layer processor. In otherembodiments, the DAS transport physical layer processor 208 is anothertype. In exemplary embodiments, the host network interfaces 202, thephysical layer processors 204, the distributed antenna system mediumaccess control layer processor 206, the DAS transport physical layerprocessor 208 and/or master host clock unit 210 are implemented in wholeor in part by optional processor 212 and memory 214. In exemplaryembodiments, power supply 216 provides power for the various componentsof the host unit 102A. In exemplary embodiments, the physical layerprocessors 204 are LTE physical layer processors because the signalsreceived from the corresponding host network interfaces 202 are LTEphysical layer signals. In exemplary embodiments, some of the physicallayer processors 204 are physical layer processors for radio accesstechnologies other than LTE and the physical layer signals received fromthe corresponding host network interfaces 202 are for these other radioaccess technologies. In exemplary embodiments, no physical layerprocessors 204 are included with some corresponding host networkinterfaces 202 that receive signals that are not physical layer signals.In exemplary embodiments, combinations of LTE physical layer processors204, other radio access technology physical layer processors 204, and nophysical layer processors 204 are included in host unit 102A. Inexemplary embodiments, the host unit 102 provides/distributes power toat least a first of the at least one antenna unit 104.

In the forward path, each host network interface 202 receives downlinkwireless network information transported in another format from arespective radio access network interface 108 and converts the downlinkwireless network information from the another format to the basebanddownlink wireless network information type. In exemplary embodiments,the purpose of the host network interface 202 is to convert the dataform the format used by the base station into a format acceptable to theRAT physical layer processor 204. In exemplary embodiments, at leastsome of the host network interfaces 202 communicate using digitalsignals with the radio access network interfaces 108. In exemplaryembodiments, at least some of the host network interfaces 202communicate using analog signals (such as radio frequency (RF) and/orintermediate frequency (IF) analog signals) with the radio accessnetwork interfaces 108. In exemplary embodiments, a host networkinterface 202 is connected to an analog radio access network interface108, such as a small cell, and the host exchanges analog RF with theanalog radio access network interface 108 and the host 102A includes adigital front end (such as within the host network interface 202 orbetween the host network interface 202 and the RAT physical layerprocessor 204) to convert between the RF and the stream of bitsexchanged with the RAT physical layer processor 204.

In specific implementations, at least one host network interface 108receives Common Public Radio Interface (CPRI) signals from a CPRIinterface of a base band unit acting as the radio access networkinterface 108, converts the CPRI signals into a format compatible withthe RAT physical layer processor. In one embodiment of a CPRI interface,the data is in an LTE PHY format and has already been coded, modulated,and fully processed according to the LTE PHY specifications. It is anI/Q stream coming from the radio access network interface 108. The LTEPHY processor (RAT physical layer processor 204-1) in the host unit 102Awould basically undo the LTE PHY processing that was done by the BBU(radio access network interface 108). The LTE physical layer data (RATphysical layer data) is translated into the LTE MAC PDUs (RAT MAC PDUs)by the LTE PHY processor (RAT physical layer processor 204). The DAS MAC(transport medium access control (MAC) processor 206), which may beimplemented as an FPGA, determines what to do with these LTE MAC PDUs(RAT MAC PDUs) including how to frame them, format them, and put theminto their own structure that is required for transport over the digitalcommunication medium 106 (such as Category building cable or other lowerbandwidth cable).

In the reverse path, each host network interface 202 receives uplinkwireless network information in the RAT physical format and convertsthem into a format for communication with the respective radio accessnetwork interface 108. In specific implementations, at least one hostnetwork interface 108 receives uplink physical layer data signals andconverts the uplink physical layer data signals into uplink CPRI signalsand communicates the CPRI signals to the at least one radio accessnetwork interface 108.

In the forward path, each physical layer processor 204 receives downlinkphysical layer data signals and converts the downlink physical layerdata signals in the physical layer to downlink medium access control(MAC) layer protocol data units (PDUs) in the medium access control(MAC) layer, wherein the medium access control layer uses relevant bitsmore efficiently than the physical layer. In the reverse path, eachphysical layer processor 204 receives uplink RAT MAC layer protocol dataunits in the RAT MAC layer and converts the uplink RAT MAC layer PDUs touplink physical layer data signals.

In exemplary embodiments, the physical layer processor 204 in the hostunit 102 performs functions similar to a user equipment (UE) device inthat it receives the RAT physical signals and reverses the physicalprocessor performed by the radio access network. In the uplink thephysical layer processor 204 in the host unit 102 creates an uplinkphysical signal representation of the wireless network information suchthat the radio access network to which the host unit 102 is connectedthrough the radio access network interface 108 can perform its normaluplink processing. In exemplary embodiments, the DAS processing istransparent to the radio access network interface 108 and the radioaccess network generally as well as the user equipment (UE).

In the forward path, the DAS MAC layer processor 206 converts thedownlink RAT MAC PDUs in the RAT MAC into downlink distributed antennasystem (DAS) transport medium access control (MAC) layer protocol dataunits (PDUs) in a downlink distributed antenna system (DAS) transportmedium access control (MAC) layer for transport through the distributedantenna system (DAS). In the reverse path, the DAS MAC layer processor206 converts the uplink distributed antenna system (DAS) transportmedium access control (MAC) layer protocol data units (PDUs) in anuplink distributed antenna system (DAS) transport medium access control(MAC) layer into uplink medium access control (MAC) layer protocol dataunits (PDUs) in the medium access control (MAC) layer. In exemplaryembodiments, the DAS MAC layer processor 206 also broadcasts signals toa plurality of different remote antenna units 104. In exemplaryembodiments, the DAS MAC layer processor 206 also combines uplink DAStransport MAC layer PDUs from different antenna units 104 in anintelligent way. In exemplary embodiments, multiple received uplink datastreams are combined using summation (either digital or analog),weighted summation, averaging, multiplexing, etc. In exemplaryembodiments, combining in the upstream occurs by recovering the RAT MACPDUs (such as LTE MAC PDUs) for all the signals to be combined and thenhaving a plurality of RAT physical layer processors 204 (such as LTE PHYprocessors) individually process the signals from RAT MAC PDUs (such asLTE MAC PDUs) into I/Q samples, which are then digitally combined in acombiner that may be within a host network interface 202 or in betweenthe RAT physical layer processors 204 and a host network interface 202.In other embodiments, the DAS MAC PDUs from the multiple remote units104 are combined bitwise by the DAS MAC processor 206. In exemplaryembodiments, the combining is done through majority logic and/orweighted combining. In exemplary embodiments, all the signals need to besynchronized so the host unit 102A knows which bit goes with which bitand so the combining results in accurate data. In exemplary embodiments,the antenna units 104 are synchronized with the host unit 102. Inexemplary embodiments, the DAS MAC layer processor 206 determineswhether multiple antenna units 104 received signals from a particularremote/subscriber unit 112 and whether there is valid data coming frommultiple antenna units 104. If there is valid data coming from multipleantenna units 104, the DAS MAC layer processor 206 will combine thebits. Because there are RAT physical layer processors 406 (such as LTEPHY processors) at the antenna units 104 (described below), the RATphysical layer processors 406 at the antenna units 104 could generatequality measurements, such as a signal to noise ratio (SNR), modulationquality, etc. and then feedback the quality metrics to the host unit102A to use in weighing and combining of the signals.

In the forward path, the DAS transport physical layer processor 208converts the downlink DAS transport MAC layer PDUs in the downlink DAStransport MAC layer into downlink DAS physical layer data streams in theDAS physical layer and communicates the downlink DAS physical layer datastreams across the at least one digital communication medium 106 to theat least one antenna unit 104. In the reverse path, the DAS transportphysical layer processor 208 receives uplink DAS physical layer datastreams in the DAS physical layer from the at least one digitalcommunication medium 106 and converts the uplink DAS physical layer datastreams into uplink DAS transport MAC layer PDUs in the uplink DAStransport MAC layer.

In exemplary embodiments, the antenna units 104 are synchronized witheach other and/or the host unit 102. In exemplary embodiments, theantenna units 104 and/or the host unit 102 are synchronized based on aclock signal propagated from the host unit 102 that is generated from asignal received by the host unit 102 from the radio access networkinterface 108 (such as a baseband unit BBU and/or small cell) so thenetwork synchronization of the radio access network interface 108 (suchas a baseband unit BBU and/or small cell) is propagated through to thevarious components of the distributed antenna system 100. In exemplaryembodiments, the master host clock unit 210 extracts the masterreference clock from a signal supplied by at least one radio accessnetwork interface 108. In exemplary embodiments, the master clock unit210 distributes the master reference clock to other components of thedistributed antenna system 100 in the downlink. In exemplaryembodiments, the master host clock unit 210 distributes this masterclock with other radio access network interfaces 108 through thecorresponding host network interfaces 202. In exemplary embodiments(such as those where the radio access network interface is an analogradio frequency interface), the master host clock unit 210 generates amaster reference clock and distributes the generated master referenceclock with radio access network interfaces 108 through the correspondinghost network interfaces 202.

FIG. 2B is a block diagram of an exemplary embodiment of a host unit102, host unit 102B, used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. Exemplaryhost unit 102B includes at least one host network interface 202(including host network interface 202-1 and any quantity of optionalhost network interfaces 202 through optional host network interface202-B), a distributed antenna system (DAS) medium access control (MAC)layer processor 206, an DAS transport physical layer processor 208, anoptional master host clock unit 210, an optional processor 212, optionalmemory 214, and an optional power supply 216. In exemplary embodiments,the host network interfaces 202, the DAS MAC layer processor 206, theDAS transport physical layer processor 208 and/or master host clock unit210 are implemented in whole or in part by optional processor 212 andmemory 214. In exemplary embodiments, power supply 216 provides powerfor the various components of the host unit 102B. Host unit 102Bincludes similar components to host unit 102A and operates according tosimilar principles and methods as host unit 102A described above.

The difference between host unit 102B and host unit 102A is that hostunit 102B does not include any RAT physical layer processors 204. Inexemplary embodiments, the LTE PHY processor (RAT physical layerprocessor 204) is not necessary in the host unit 102A because the hostunit 102A receives the LTE MAC PDUs (RAT MAC PDUs) directly from thebaseband unit (BBU, such as radio access network interface 108). Inexemplary embodiments, this may require changes to the baseband unit(BBU, such as radio access network interface 108) to allow output of theLTE MAC PDUs (RAT MAC PDUs) instead of the I/Q stream. In exemplaryembodiments, the RAT physical layer processor 204 is not included and/orbypassed with some signals so that I/Q samples are transmitted throughthe distributed antenna system 100 instead of the MAC PDUs. In exemplaryembodiments, this is useful with other radio access technologies (RAT)that do not require as much bandwidth for transport using I/Q basebandsamples as LTE. Accordingly, I/Q samples could be packed into a DASphysical layer compatible frame. In exemplary embodiments, this enablesdata represented in IQ space to be transported directly instead oftranslating it into the MAC PDUs for transport. The benefit of thisapproach is that the distributed antenna system 100 can be radio accesstechnology (RAT) agnostic. This could be more useful with less bandwidthhungry wireless access technology protocols, such as 2G and/or 3G radioaccess technologies (RAT). In exemplary embodiments, this approach isless complicated because it does not require the additional LTE PHYprocessors in both the host unit 102 and antenna units 104. In exemplaryembodiments, some signals go through a RAT physical layer processor 204and are converted into MAC PDUs, while others remain as I/Q samples, butall the signals can be multiplexed together and transported through thedistributed antenna system 100. This enables inputs from differentsources to be used while sharing a single cable. In exemplaryembodiments, there is some framing within the payload with both MAC PDUsand synchronous I/Q samples.

Accordingly and in the forward path, the DAS MAC layer processor 206converts the downlink RAT MAC data signals in the MAC layer intodownlink distributed antenna system (DAS) transport medium accesscontrol (MAC) layer protocol data units (PDUs) in a downlink distributedantenna system (DAS) transport medium access control (MAC) layer fortransport through the distributed antenna system (DAS). In the reversepath, the DAS MAC layer processor 206 converts the uplink distributedantenna system (DAS) transport medium access control (MAC) layerprotocol data units (PDUs) in an uplink distributed antenna system (DAS)transport medium access control (MAC) layer into RAT MAC layer datasignals in the MAC layer. This host unit 102B could be used in exemplaryembodiments where the radio access network interface 108 communicatesRAT MAC PDUs directly with the host network interface 202, so it is notnecessary to perform any physical RAT layer processing to get thewireless network information into the more efficient format. This hostunit 102B could also be used in exemplary embodiments where it is notnecessary to undo any physical RAT layer processing even though thesignals received from the radio access network interface 108 have hadphysical RAT layer processing, because the physical RAT layer processingis efficient enough. In exemplary embodiments, combinations of host unit102A and host unit 102B allow for some wireless network information tohave the physical RAT layer processing undone using a physical layerprocessor and others to not have it undone, so a physical layerprocessor 204 is not necessary.

FIGS. 3A-3J are block diagrams of exemplary embodiments of base stationhost network interfaces 302 used in distributed antenna systems, such asthe exemplary distributed antenna systems 100 described above. Each ofFIGS. 3A-3J illustrates a different embodiment of a type of host networkinterface 202, labeled 104A-104D respectively.

FIG. 3A is a block diagram of an exemplary embodiment of a host networkinterface 202, general host network interface 202A. General host networkinterface 202A includes signal to data stream conversion module 302A,network interface clock unit 304A, optional processor 306, optionalmemory 308, and optional power supply 310. In exemplary embodiments,signal to data stream conversion module 302A is communicatively coupledto a radio access network interface output 312A of a radio accessnetwork interface 108A. Signal to data stream conversion module 302A isalso communicatively coupled to at least physical layer processor 204.In exemplary embodiments, the signal to data stream conversion module302A and/or the network interface clock unit 304A are implemented usingoptional processor 306 and optional memory 308. In exemplaryembodiments, the optional power supply 310 provides power to the variouselements of the host network interface 202A.

In the downlink, signal to data stream conversion module 302A isconfigured to receive downlink signals from the radio access networkinterface output 312A of the radio access network interface 108A. Thesignal to data stream conversion module 302A is further configured toconvert the received downlink signals to a downlink data stream. In theuplink, signal to data stream conversion module 302A is configured toreceive an uplink data stream from an physical layer processor 204. Thesignal to data stream conversion module 302A is further configured toconvert the uplink data stream to uplink signals. Signal to data streamconversion module 302A is further configured to communicate the uplinksignals to the radio access network interface output 312A of the radioaccess network interface 108A.

In exemplary embodiments, the network interface clock unit 304A iscommunicatively coupled to a radio access network interface clock unit314A of the radio access network interface 108A. In exemplaryembodiments, a master reference clock is provided from the radio accessnetwork interface clock unit 314A of the radio access network interface108A to the network interface clock unit 304A of the host networkinterface 202A. In other exemplary embodiments, a master reference clockis provided to the radio access network interface clock unit 314A of theradio access network interface 108A from the network interface clockunit 304A of the host network interface 202A.

FIG. 3B is a block diagram of an exemplary embodiment of a type of basestation interface 102, general host network interface 202B. General hostnetwork interface 202B includes signal to data stream conversion module302B, network interface clock unit 304B, optional processor 306,optional memory 308, and optional power supply 310. Similarly to generalhost network interface 202A, signal to data stream conversion module302B is communicatively coupled to a radio access network interfaceoutput 312B of a radio access network interface 108B. In contrast togeneral host network interface 202A, base station network interfaceclock unit 304B is not coupled directly to radio access networkinterface clock unit 314B of radio access network interface 108B toprovide the master reference clock to the network interface clock unit304B. Instead, radio access network interface clock unit 314B providesthe master reference clock to the radio access network interface output312B and the master reference clock is embedded in the downstream signalfrom the radio access network interface output 312B to the signal todata stream conversion module 302B of the host network interface 202B,which then provides it to the network interface clock unit 304B.

In exemplary embodiments where the master reference clock is providedfrom an radio access network interface 108B to the distributed antennasystem 100, the master reference clock can be embedded in the downlinksignals by the radio access network interface clock unit 314B so thatthe downlink signals communicated from the radio access networkinterface output 312B of the radio access network interface 108B to thesignal to data stream conversion module 302B can be extracted by thenetwork interface clock unit 304B and distributed as appropriate withinthe host network interface 202B and the distributed antenna system 100generally. In exemplary embodiments, the signal to data streamconversion module 302B and/or the network interface clock unit 304B areimplemented using optional processor 306 and optional memory 308. Inexemplary embodiments, the optional power supply 310 provides power tothe various elements of the host network interface 202B.

FIG. 3C is a block diagram of an exemplary embodiment of a type of hostnetwork interface 202, baseband host network interface 202C. Basebandhost network interface 202C includes a baseband to data streamconversion module 302C, a baseband network interface clock unit 304C, anoptional processor 306, optional memory 308, and an optional powersupply 310. In exemplary embodiments, baseband to data stream conversionmodule 302C is communicatively coupled to a baseband base station output312C of a radio access network interface that is a baseband base station108C. Baseband to data stream conversion module 302C is alsocommunicatively coupled to at least one physical layer processor 204. Inexemplary embodiments, the baseband to data stream conversion module302C and/or the baseband network interface clock unit 304C areimplemented using optional processor 306 and optional memory 308. Inexemplary embodiments, the optional power supply 310 provides power tothe various elements of the baseband host network interface 202C.

In the downlink, baseband to data stream conversion module 302C isconfigured to receive baseband mobile wireless access signals (such asI/Q data) from a baseband base station output 312C of a baseband basestation 108C. The baseband to data stream conversion module 302C isfurther configured to convert the received baseband mobile wirelessaccess signals to a downlink data stream. In the uplink, baseband todata stream conversion module 302C is configured to receive a datastream from physical layer processor 204. The baseband to data streamconversion module 302C is further configured to convert the uplink datastream to uplink baseband wireless access signals. Baseband to datastream conversion module 302C is further configured to communicate theuplink baseband wireless access signals to the baseband base stationoutput 312C.

In exemplary embodiments, the baseband network interface clock unit 304Cis communicatively coupled to a baseband base station clock unit 314C ofthe baseband base station 108C. In exemplary embodiments, a masterreference clock is provided from the baseband base station clock unit314C of the baseband base station 108C to the baseband network interfaceclock unit 304C of the baseband host network interface 202C. Inexemplary embodiments, a master reference clock is provided to thebaseband base station clock unit 314C of the baseband base station 108Cfrom the baseband network interface clock unit 304C of the baseband hostnetwork interface 202C.

FIG. 3D is a block diagram of an exemplary embodiment of a type of basestation interface 102, baseband network interface 202D. Baseband networkinterface 202D includes a baseband to data stream conversion module302D, a baseband network interface clock unit 304D, an optionalprocessor 306, optional memory 308, and an optional power supply 310.Similarly to baseband host network interface 202C, baseband to datastream conversion module 302D is communicatively coupled to a basebandbase station output 312D of a radio access network interface that is abaseband base station 108D and to at least one physical layer processor204. In contrast to baseband host network interface 202C, basebandnetwork interface clock unit 304D is not coupled directly to basebandbase station clock unit 314D of baseband base station 108D to provideand/or receive the master reference clock to/from the baseband basestation 108D. Instead, baseband base station output 312D provides themaster reference clock to the baseband to data stream conversion module302D and the master reference clock is embedded in downstream signalsfrom the baseband base station output 312D of baseband base station 108Dto the baseband to data stream conversion module 302D of the basebandnetwork interface 202D.

In exemplary embodiments where the master reference clock is providedfrom the baseband base station 108D to the distributed antenna system,the master reference clock can be embedded in the downlink signals bythe baseband base station clock unit 314D so that the downlink signalscommunicated from the baseband base station output 312D of the basebandbase station 108D to the baseband to data stream conversion module 302Dcan be extracted by the baseband network interface clock unit 304D anddistributed as appropriate within the baseband network interface 202Dand the distributed antenna system generally. In exemplary embodiments,the baseband to data stream conversion module 302D and/or the basebandnetwork interface clock unit 304D are implemented using optionalprocessor 306 and optional memory 308. In exemplary embodiments, theoptional power supply 310 provides power to the various elements of thebaseband network interface 202D.

FIG. 3E is a block diagram of an exemplary embodiment of a type of hostnetwork interface 202, Common Public Radio Interface (CPRI) host networkinterface 202E. CPRI host network interface 202E includes a CPRI to datastream conversion module 302E, a CPRI network interface clock unit 304E,an optional processor 306, optional memory 308, and an optional powersupply 310. In exemplary embodiments, CPRI to data stream conversionmodule 302E is communicatively coupled to a CPRI base station output312E of a host network interface 202 that is a CPRI base station 108E.CPRI to data stream conversion module 302E is also communicativelycoupled to at least one physical layer processor 204. In exemplaryembodiments, the CPRI to data stream conversion module 302E and/or theCPRI network interface clock unit 304E are implemented using optionalprocessor 306 and optional memory 308. In exemplary embodiments, theoptional power supply 310 provides power to the various elements of theCPRI host network interface 202E.

In the downlink, CPRI to data stream conversion module 302E isconfigured to receive CPRI signals from the CPRI base station output312E. The CPRI to data stream conversion module 302E is furtherconfigured to convert the received CPRI signals to a downlink datastream. In the uplink, CPRI to data stream conversion module 302G isconfigured to receive a data stream from physical layer processor 204.The CPRI to data stream conversion module 302E is further configured toconvert the uplink data stream to uplink CPRI signals. CPRI to datastream conversion module 302E is further configured to communicate theuplink CPRI signal to the CPRI base station output 312E.

In exemplary embodiments, the CPRI network interface clock unit 304E iscommunicatively coupled to a CPRI base station clock unit 314E of theCPRI base station 108E. In exemplary embodiments, a master referenceclock is provided from the CPRI base station clock unit 314E of the CPRIbase station 108E to the CPRI network interface clock unit 304C of theCPRI host network interface 202E. In other exemplary embodiments, amaster reference clock is provided to the CPRI base station clock unit314E of the CPRI base station 108E from the CPRI network interface clockunit 304E of the CPRI host network interface 202E.

FIG. 3F is a block diagram of an exemplary embodiment of a type of basestation interface 102, CPRI host network interface 202F. CPRI hostnetwork interface 202F includes a CPRI to data stream conversion module302F, a CPRI network interface clock unit 304F, an optional processor306, optional memory 308, and an optional power supply 310. Similarly toCPRI host network interface 202E, CPRI to data stream conversion module302F is communicatively coupled to a CPRI base station output 312F of aradio access network interface 108 that is a CPRI base station 108F andto at least one physical layer processor 204. In contrast to CPRI hostnetwork interface 202E, CPRI network interface clock unit 304F is notcoupled directly to CPRI base station clock unit 314E of CPRI basestation 108F to provide and/or receive the master reference clockto/from the CPRI base station 108F. Instead, CPRI to data streamconversion module 302F provides the master reference clock to the CPRIhost network interface 202F and the master reference clock is embeddedin downstream signals from the CPRI base station output 312F of the CPRIbase station 108F to the CPRI to data stream conversion module 302F ofCPRI network interface 202F.

In exemplary embodiments where the master reference clock is providedfrom the CPRI base station 108F to the distributed antenna system 100,the master reference clock can be embedded in the downlink signals bythe CPRI base station clock unit 314F so that the downlink signalscommunicated from the CPRI base station output 312F of the CPRI basestation 108F to the CPRI to data stream conversion module 302F can beextracted by the CPRI network interface clock unit 304F and distributedas appropriate within the CPRI host network interface 202F and thedistributed antenna system 100 generally. In exemplary embodiments, theCPRI to data stream conversion module 302F and/or the CPRI networkinterface clock unit 304F are implemented using optional processor 306and optional memory 308. In exemplary embodiments, the optional powersupply 310 provides power to the various elements of the CPRI hostnetwork interface 202F.

FIG. 3G is a block diagram of an exemplary embodiment of a type of hostnetwork interface 202, radio frequency (RF) host network interface 202G.Radio frequency host network interface 202G includes a radio frequency(RF) to data stream conversion module 302G, a radio frequency (RF)network interface clock unit 304G, an optional processor 306, optionalmemory 308, and an optional power supply 310. In exemplary embodiments,radio frequency (RF) to data stream conversion module 302G iscommunicatively coupled to a radio frequency (RF) base station output312G of a radio access network interface that is a radio frequency basestation 108G. Radio frequency to data stream conversion module 302G isalso communicatively coupled to at least one physical layer processor204. In exemplary embodiments, the radio frequency to data streamconversion module 302G and/or the radio frequency network interfaceclock unit 304G are implemented using optional processor 306 andoptional memory 308. In exemplary embodiments, the optional power supply310 provides power to the various elements of the radio frequency hostnetwork interface 202G.

In the downlink, radio frequency to data stream conversion module 302Gis configured to receive radio frequency signals from the radiofrequency base station output 312G of the radio frequency base station108G. The radio frequency to data stream conversion module 302G isfurther configured to convert the received radio frequency signals to adownlink data stream. In exemplary embodiments, this is done usingoscillators and mixers. In the uplink, radio frequency to data streamconversion module 302G is configured to receive a data stream fromphysical layer processor 204. The radio frequency to data streamconversion module is further configured to convert the uplink datastream to radio frequency signals. In exemplary embodiments, this isdone using oscillators and mixers. Radio frequency to data streamconversion module 302G is further configured to communicate the uplinkradio frequency signals to the radio frequency base station output 312Gof the radio frequency base station 108G.

In exemplary embodiments, the radio frequency network interface clockunit 304G is communicatively coupled to a radio frequency base stationclock unit 314G of the radio frequency base station 108G. In exemplaryembodiments, a master reference clock is provided from the radiofrequency base station clock unit 314G of the radio frequency basestation 108G to the radio frequency network interface clock unit 304G ofthe radio frequency host network interface 202G. In other exemplaryembodiments, a master reference clock is provided to the radio frequencybase station clock unit 314G of the radio frequency base station 108Gfrom the radio frequency network interface clock unit 304G of the hostnetwork interface 202G.

FIG. 3H is a block diagram of an exemplary embodiment of a type of basestation interface 102, radio frequency (RF) host network interface 202H.Radio frequency host network interface 202H includes a radio frequency(RF) to data stream conversion module 202H, a radio frequency (RF)network interface clock unit 204H, an optional processor 306, optionalmemory 308, and an optional power supply 310. Similarly to radiofrequency host network interface 202G, radio frequency (RF) to datastream conversion module 202H is communicatively coupled to a radiofrequency (RF) base station output 212H of a radio access networkinterface 108 that is a radio frequency base station 108H and to atleast one physical layer processor 204. In contrast to radio frequencyhost network interface 202G, radio frequency network interface clockunit 204H is not coupled directly to radio frequency base station clockunit 214H of radio frequency base station 108H to provide and/or receivethe master reference clock to/from the radio frequency base station108H. Instead, radio frequency to data stream conversion module 202Hprovides the master reference clock to the radio frequency networkinterface clock unit 304G and the master reference clock is embedded indownstream signals from the RF base station output 312H of the RF basestation 108H to the RF to data stream conversion module 302H of the RFnetwork interface 202H.

In exemplary embodiments where the master reference clock is providedfrom the radio frequency base station 108H to the distributed antennasystem, the master reference clock can be embedded in the downlinksignals by the radio frequency base station clock unit 214H so that thedownlink signals communicated from the radio frequency base stationoutput 212H of the radio frequency base station 108H to the radiofrequency to data stream conversion module 202H can be extracted by theradio frequency network interface clock unit 204H and distributed asappropriate within the radio frequency host network interface 202H andthe distributed antenna system 100 generally. In exemplary embodiments,the radio frequency to data stream conversion module 202H and/or theradio frequency network interface clock unit 204H are implemented usingoptional processor 306 and optional memory 308. In exemplaryembodiments, the optional power supply 310 provides power to the variouselements of the host network interface 202H.

FIG. 3I is a block diagram of an exemplary embodiment of a type of hostnetwork interface 202, Ethernet network interface 202I. Ethernet networkinterface 202I includes an Ethernet to data stream conversion module302I, an Ethernet network interface clock unit 304I, an optionalprocessor 306, optional memory 308, and an optional power supply 310. Inexemplary embodiments, Ethernet to data stream conversion module 302I iscommunicatively coupled to an Ethernet output 312I of an external devicethat is an Ethernet adapter 108I to an internet protocol (IP) basednetwork. Ethernet to data stream conversion module 302I is alsocommunicatively coupled to at least one physical layer processor 204. Inexemplary embodiments, the Ethernet to data stream conversion module302I and/or the Ethernet network interface clock unit 304I areimplemented using optional processor 306 and optional memory 308. Inexemplary embodiments, the optional power supply 310 provides power tothe various elements of the Ethernet network interface 202I.

In the downlink Ethernet to data stream conversion module 302I isconfigured to receive internet protocol packets from the Ethernet output312I. The Ethernet to data stream conversion module 302I is furtherconfigured to convert the internet protocol packets to a downlink datastream. In the uplink, Ethernet to data stream conversion module 302I isconfigured to receive a data stream from physical layer processor 204.The Ethernet to data stream conversion module 302I is further configuredto convert the uplink data stream to uplink Ethernet frames. Ethernet todata stream conversion module 302I is further configured to communicatethe uplink Ethernet frames to the Ethernet output 304I.

In exemplary embodiments, the Ethernet network interface clock unit 304Iis communicatively coupled to an Ethernet adapter clock unit 314I of theEthernet adapter 108I. In exemplary embodiments, a master referenceclock is provided from the Ethernet adapter clock unit 314I of theEthernet adapter 108I to the Ethernet network interface clock unit 304Iof the Ethernet network interface 202I. In other exemplary embodiments,a master reference clock is provided to the Ethernet adapter clock unit314I of the Ethernet adapter 108I from the Ethernet network interfaceclock unit 304I of the Ethernet network interface 202I.

FIG. 3J is a block diagram of an exemplary embodiment of a type of basestation interface 102, an Ethernet network interface 202J. Ethernetnetwork interface 202J includes an Ethernet to data stream conversionmodule 302J, an Ethernet network interface clock unit 304J, an optionalprocessor 306, optional memory 308, and an optional power supply 310.Similarly to Ethernet network interface 202I, Ethernet to data streamconversion module 302J is communicatively coupled to an Ethernet output312J of an external device that is an Ethernet adapter 108J and to atleast one physical layer processor 204. In contrast to Ethernet networkinterface 202I, Ethernet network interface clock unit 304J is notcoupled directly to Ethernet adapter clock unit 314J of Ethernet adapter108J to provide and/or receive the master reference clock to/from theEthernet adapter 108J. Instead, Ethernet output 312J provides the masterreference clock to the Ethernet to data stream conversion module 302Jand the master reference clock is embedded in downstream signals fromthe Ethernet output 312J of the Ethernet adapter 108J to the Ethernet todata stream conversion module 302J of the Ethernet network interface202J.

In exemplary embodiments where the master reference clock is providedfrom the Ethernet adapter 108J to the distributed antenna system 100,the master reference clock can be embedded in the downlink signals bythe Ethernet adapter clock unit 314J so that the downlink signalscommunicated from the Ethernet output 312J of the Ethernet adapter 108Jto the Ethernet to data stream conversion module 302J can be extractedby the Ethernet network interface clock unit 304J and distributed asappropriate within the Ethernet network interface 202J and thedistributed antenna system 100 generally. In exemplary embodiments, theEthernet to data stream conversion module 302J and/or the Ethernetnetwork interface clock unit 304J are implemented using optionalprocessor 306 and optional memory 308. In exemplary embodiments, theoptional power supply 310 provides power to the various elements of theEthernet network interface 202J.

FIGS. 4A-4B are block diagrams of exemplary embodiments of antenna unit104. Each of FIGS. 4A-4B illustrates a different embodiment of a remoteunit 104, labeled 104A-104B respectively.

FIG. 4A is a block diagram of an exemplary embodiment of a remote unit104, remote unit 104A, used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. The antennaunit 104 includes a distributed antenna system (DAS) transport physicallayer processor 402, a distributed antenna system (DAS) medium accesscontrol (MAC) layer processor 404, a radio access technology (RAT)physical layer processor 406, a radio frequency (RF) conversion module408, optional antenna unit clock unit 410, optional processor 412,optional memory 414, and optional power supply 416. In exemplaryembodiments, the distributed antenna system (DAS) transport physicallayer processor 402 is replaced with another type of Layer 1 (L1)processor for a transport Layer 1. In exemplary embodiments, the DAStransport physical layer processor 402 is an Ethernet physical layerprocessor. In other embodiments, the DAS transport physical layerprocessor 402 is another type. In exemplary embodiments, the distributedantenna system (DAS) medium access control (MAC) layer processor 404 isreplaced with another type of Layer 2 (L2) processor for a transportLayer 2. In exemplary embodiments, the radio access technology (RAT)physical layer processor 406 is replaced with another type of Layer 1(L1) processor for a radio access technology (RAT) Layer 1. In exemplaryembodiments, DAS transport physical layer processor 402, distributedantenna system medium access control layer processor 404, RAT physicallayer processor 406, and/or radio frequency conversion module 408 areimplemented at least in part by optional processor 412 and memory 414.In exemplary embodiments, power for the antenna unit is provided by thehost unit 102 remotely across a medium and the optional power supply 416derives and/or extracts power from the medium. In exemplary embodiments,optional power supply 416 is used to power the various components of theantenna unit 104.

In exemplary embodiments, the DAS transport physical layer processor 402is configured to receive a downlink physical layer data stream from thehost unit 102 across the digital communication link 106 and converts thedownlink physical layer data stream in the physical layer to downlinkdistributed antenna system (DAS) transport medium access control (MAC)layer protocol data units (PDU). In exemplary embodiments, the DAStransport physical layer processor 402 is an Ethernet PHY thatessentially undoes the processing of the corresponding DAS transportphysical layer processor 208 in the host unit 102. In exemplaryembodiments, more input lines are included in the antenna unit 104A. Inexemplary embodiments, the distributed antenna system (DAS) mediumaccess control (MAC) layer processor 404 is configured to convert thedownlink distributed antenna system transport medium access controllayer protocol data units in the downlink distributed antenna systemtransport medium access control layer into downlink medium accesscontrol layer protocol data units in the medium access control layer.

In exemplary embodiments, the RAT physical layer processor 406 isconfigured to generate a downlink RAT signal from the downlink mediumaccess control layer protocol data units in the medium access controllayer. In exemplary embodiments, the RF conversion module 404 convertsthe baseband downlink RAT signal to radio frequency signals fortransmission at antenna 110. In exemplary embodiments, the RAT physicallayer processors 406 are LTE physical layer processors because thesignals communicated with the RF conversion module 404 need to be LTEphysical layer signals. In these embodiments, the LTE physical layerprocessors process OFDM in the downlink and SC-FDMA in the uplink. Inexemplary embodiments, the LTE physical layer processor (RAT physicallayer processor 406) in the remote antenna unit 104A doesn't perform theupper layer processing (L2/L3) in the protocol stack, rather it onlyperforms the Layer 1 processing up to the creation of the MAC layerdata.

In exemplary embodiments, some of the RAT physical layer processors 406are physical layer processors for radio access technologies other thanLTE and the physical layer signals received from the corresponding hostnetwork interfaces 202 are for these other radio access technologies. Inexemplary embodiments, no RAT physical layer processors 406 are includedwhen the RAT physical layer data is transported in some format from thehost 102 to the antenna unit 104A. In exemplary embodiments,combinations of LTE physical layer processors 406, other RAT physicallayer processors 406, and no RAT physical layer processors 406 areincluded in antenna unit 104A.

In exemplary embodiments, the RF conversion module 408 receives signalsfrom antenna 110 and converts radio frequency signals to a basebanduplink RAT signal. In exemplary embodiments, the RAT physical layerprocessor 406 is configured to receive the baseband uplink RAT signalfrom the RF conversion module 408 and to generate uplink medium accesscontrol layer protocol data units in the medium access control layerfrom the baseband uplink RAT signal. In exemplary embodiments, thedistributed antenna system (DAS) medium access control (MAC) layerprocessor 404 is configured to convert the uplink medium access controllayer protocol data units in the medium access control layer into uplinkdistributed antenna system transport medium access control layerprotocol data units in the uplink distributed antenna system transportmedium access control layer. In exemplary embodiments, the DAS transportphysical layer processor 402 is configured to convert the uplinkdistributed antenna system transport medium access control layerprotocol data units to an uplink physical layer DAS data stream and tocommunicate the uplink physical layer DAS data stream to the host unit102 across the digital communication link 106.

FIG. 4B is a block diagram of an exemplary embodiment of a remote unit104, remote unit 104B, used in distributed antenna systems, such as theexemplary distributed antenna systems 100 described above. The antennaunit 104B includes an DAS transport physical layer processor 402, adistributed antenna system (DAS) medium access control (MAC) layerprocessor 404, a plurality of radio access technology (RAT) physicallayer processors 406 (including RAT physical layer processor 406-1, RATphysical layer processor 406-2, and any quantity of optional RATphysical layer processors 406 through optional RAT physical layerprocessor 406-G), a plurality of radio frequency (RF) conversion modules408, optional antenna unit clock unit 410, optional processor 412,optional memory 414, and optional power supply 416. In exemplaryembodiments, DAS transport physical layer processor 402, distributedantenna system medium access control layer processor 404, RAT physicallayer processor 406, and/or radio frequency conversion module 408 areimplemented at least in part by optional processor 412 and memory 414.In exemplary embodiments, optional power supply 416 is used to power thevarious components of the antenna unit 104. Antenna unit 104B includessimilar components to antenna unit 104A and operates according tosimilar principles and methods as antenna unit 104A described above.

The differences between antenna unit 104A and antenna unit 104B is thatantenna unit 104B includes a plurality of radio access technology (RAT)physical layer processors 406 (such as RAT physical layer processor406-1 through optional RAT physical layer processor 406-G), a pluralityof RF conversion modules 408 (such as RF conversion module 408-1 throughRF conversion module 408-C), and optional Ethernet interface 420. Inexemplary embodiments, each of the radio access technology (RAT)physical layer processors 406 is replaced with another type of Layer 1(L1) processors for a radio access technology (RAT) Layer 1. Inexemplary embodiments, the DAS MAC layer processor 404 includesmultiplexing functionality enabling multiple different signals to bereceived and multiplexed in different ways. In exemplary embodiments,such as MIMO applications or multi-signal applications, the DAS MAClayer processor 404 multiplexes the data for the different signals ontothe same DAS transport physical layer processor 402 for transport acrossthe digital communication link 106 to the host unit 102. In exemplaryembodiments, the DAS MAC layer processor 404 receives a plurality ofuplink data streams from a plurality of RF conversion modules 408. Inexemplary embodiments, the DAS MAC layer processor 404 aggregates atleast one uplink data stream received from an RF conversion module 408-1with another uplink data stream received from another RF conversionmodule 408-2. In exemplary embodiments, the DAS MAC layer processor 404aggregates a plurality of uplink data streams into an aggregate uplinkdata stream that is transmitted through the DAS transport physical layerprocessor 402.

In exemplary embodiments, more than one RAT physical layer processor 406is communicatively coupled to a single RF conversion module 408. Forexample, both optional RAT physical layer processor 406-3 and optionalRAT physical layer processor 406-4 being communicatively coupled tosingle RF conversion module 408-3. In these embodiments, more than oneRAT physical layer data steam is communicated to a single RF conversionmodule. In exemplary embodiments, the RAT physical layer data streamfrom a plurality of RAT physical layer processors 406 are in the sameband of operation (such as two different two different LTE signals, anLTE signal and a UMTS signal, etc.), such that they can be convertedsimultaneously by a single RF conversion module 408. In exemplaryembodiments, the two different signals from the two different RATphysical layer data streams are combined digitally at baseband andupconverted simultaneously using RF conversion module 408 using a singlepower amplifier.

In exemplary embodiments, the optional Ethernet interface 408 receives adownlink data stream from the DAS MAC layer processor 404 and convertsit to Ethernet packets and communicates the Ethernet packets with aninternet protocol network device. The optional Ethernet interface 408also receives Ethernet packets from the internet protocol network deviceand converts them to an uplink data stream and communicates it to theDAS MAC layer processor 404. In exemplary embodiments, the DAS MAC layerprocessor 404 also multiplexes the uplink data stream from the Ethernetpackets with the uplink data streams from the RF conversion modules 408.The optional Ethernet interface 408 is an example of how the additionalbandwidth freed up through the methods described herein can be used toallow for additional services, such as an Ethernet pipe from the hostunit 102 to at least one antenna unit 104.

In exemplary embodiments, the optional antenna unit clock unit 410extracts the master reference clock from the downlink data stream anduses this master clock within the antenna unit 104 to establish a commontime base in the antenna unit 104 with the rest of the distributedantenna system 100. In exemplary embodiments, the optional antenna unitclock unit 410 generates a master reference clock and distributes thegenerated master reference clock to other components of the distributedantenna system 100 (and even the radio access network interfaces 108) inthe upstream using the uplink data stream.

FIGS. 5A-5C are block diagrams of exemplary embodiments of RF conversionmodules 404 used in antenna units of distributed antenna systems, suchas the exemplary antenna unit 100 described above. Each of FIGS. 5A-5Care block diagrams of exemplary embodiments of RF conversion module 404,labeled RF conversion module 404A-404D respectively.

FIG. 5A is a block diagram of an exemplary RF conversion module 404Aincluding an optional data stream conditioner 502, an RF frequencyconverter 504, an optional RF conditioner 506, and an RF duplexer 508coupled to a single antenna 110.

The optional data stream conditioner 502 is communicatively coupled to aRAT physical layer processor 406 and the radio frequency (RF) converter504. In the forward path, the optional data stream conditioner 502conditions the downlink data stream (for example, through amplification,attenuation, and filtering) received from the RAT physical layerprocessor 406 and passes the downlink data stream to the RF converter504. In the reverse path, the optional data stream conditioner 502conditions the uplink data stream (for example, through amplification,attenuation, and filtering) received from the RF converter 504 andpasses the uplink data stream to the RAT physical layer processor 406.

The RF converter 504 is communicatively coupled to the physical layerprocessor or the optional data stream conditioner 502 on one side and toeither RF duplexer 508 or the optional RF conditioner 506 on the otherside. In exemplary embodiments, the main function of the RF converter504 is to convert between digital bits and radio frequency. In exemplaryembodiments, the RF converter includes analog to digital converters,digital to analog converters, as well as mixers and local oscillators.In the downstream, the RF converter 504 converts a downlink data streamto downlink radio frequency (RF) signals and passes the downlink RFsignals onto either the RF duplexer 508 or the optional RF conditioner506. In the upstream, the RF converter 504 converts uplink radiofrequency (RF) signals received from either the RF duplexer 508 or theoptional RF conditioner 506 to an uplink data stream and passes theuplink data stream to the RAT physical layer processor 406 or theoptional data stream conditioner 502.

The RF duplexer 508 is communicatively coupled to either the RFfrequency converter 504 or the optional RF conditioner 506 on one sideand the antenna 110 on the other side. The RF duplexer 508 duplexes thedownlink RF signals with the uplink RF signals fortransmission/reception using the antenna 110.

FIG. 5B is a block diagram of an exemplary RF conversion module 404Bincluding an optional data stream conditioner 502, an RF frequencyconverter 504, and an optional RF conditioner 506 coupled to a downlinkantenna 110A and an uplink antenna 110B. RF conversion module 404Bincludes similar components to RF conversion module 404A and operatesaccording to similar principles and methods as RF conversion module 404Adescribed above. The difference between RF conversion module 404B and RFconversion module 404A is that RF conversion module 404B does notinclude RF duplexer 508 and instead includes separate downlink antenna110A used to transmit RF signals to at least one subscriber unit anduplink antenna 110B used to receive RF signals from at least onesubscriber unit.

FIG. 5C is a block diagram of an exemplary RF conversion module 404Cthat communicates downstream and upstream signals using a single antenna110 through a TDD switch 510 (or other circulator). The RF conversionmodule 404D includes an optional data stream conditioner 502, an RFfrequency converter 504, an optional RF conditioner 506, and the TDDswitch 510 that is communicatively coupled to antenna 110. RF conversionmodule 404C operates according to similar principles and methods as RFconversion module 404A described above. The difference between RFconversion module 404C and RF conversion module 404A is that RFconversion module 404C uses the TDD switch 510 to switch between adownstream and upstream signal path using a single antenna 110 throughTDD switch 510. The TDD switch switches between the duplexed downlinkand uplink signals for RF conversion module 404C fortransmission/reception using the single antenna 110.

FIG. 5D is a block diagram of an exemplary RF conversion module 404D-1and exemplary RF conversion module 404D-2 that share a single antenna110 through an RF diplexer 512. The RF conversion module 404D-1 includesan optional data stream conditioner 502-1, an RF frequency converter504-1, an optional RF conditioner 506-1, and an RF duplexer 508-1communicatively coupled to RF diplexer 512 that is communicativelycoupled to antenna 110. Similarly, the RF conversion module 404D-2includes an optional data stream conditioner 502-2, an RF frequencyconverter 504-2, an optional RF conditioner 506-2, and an RF duplexer508-2 communicatively coupled to RF diplexer 512 that is communicativelycoupled to antenna 110. Each of RF conversion module 404D-1 and 404D-2operate according to similar principles and methods as RF conversionmodule 404A described above. The difference between RF conversionmodules 404D-1 and 404D-2 and RF conversion module 404A is that RFconversion modules 404D-1 and 404D-2 are both coupled to a singleantenna 110 through RF diplexer 512. The RF diplexer 512 diplexes theduplexed downlink and uplink signals for both RF conversion module404D-1 and 404D-2 for transmission/reception using the single antenna110.

FIG. 6 is a block diagram of an exemplary embodiment of a radio access(RAN) network interface 108, radio access network interface 108C, usedin distributed antenna systems, such as the exemplary distributedantenna systems 100 described above. In exemplary embodiments, exemplaryradio access network interface 108C is a baseband unit (BBU) such as anLTE BBU that has been optimized to more efficiently communicate withremote units 104 in distributed antennas systems 100. Exemplary radioaccess network interface 108C includes at least one core networkinterface 602 (including core network interface 602-1 and any quantityof optional core network interfaces 202 through optional core networkinterface 602-B), at least one Layer 2 (L2)/Layer 3 (L3) processor 604(including L2/L3 processor 604-1 and any quantity of optional L2/L3processors 604 through optional L2/L3 processor 604-B), a transportmedium access control (MAC) layer processor 606 (such as a distributedantenna system (DAS) MAC layer processor), a transport physical layerprocessor 608 (such as a distributed antenna system (DAS) physical layerprocessor), an optional radio access network interface clock unit 610,an optional processor 612, optional memory 614, and an optional powersupply 616. In exemplary embodiments, the at least one core networkinterface 602 is replaced with another type of Layer 1 (L1) and Layer 2(L2) processor for a core network Layer 1 (L1) and Layer 2 (L2). Inexemplary embodiments, the at least one L2/L3 processor 604 is replacedwith another type of Layer 2 (L2) and Layer 3 (L3) processor for a radioaccess technology (RAT) Layer 2 (L2) and Layer 3 (L3). In exemplaryembodiments, the at least one L2/L3 processor 604 is an LTE L2/L3processor. In exemplary embodiments, the transport MAC layer processor606 is replaced with another type of Layer 2 processor for a transportLayer 2. In exemplary embodiments, the transport physical layerprocessor 608 is a transport Layer 1 processor for a transport Layer 1.In exemplary embodiments, the transport physical layer processor 608 isan Ethernet physical layer processor. In other embodiments, thetransport physical layer processor 608 is another type of physical layerprocessor for transport through the distributed antenna system.

In exemplary embodiments, the core network interfaces 602, the L2/L3processors 604, the transport MAC layer processor 606, the transportphysical layer processor 608 and/or optional radio access networkinterface clock unit 610 are implemented in whole or in part by optionalprocessor 612 and memory 614. In exemplary embodiments, power supply 616provides power for the various components of the radio access networkinterface 108C. In exemplary embodiments, the L2/L3 processors 604 areLTE L2/L3 processors because the signals received from the correspondingcore network interfaces 602 are LTE core network signals, communicatedusing Internet Protocol (IP) over Gigabit Ethernet. In exemplaryembodiments, some of the L2/L3 processors 604 are L2/L3 processors forradio access technologies (RAT) other than LTE and the signals receivedfrom the corresponding core network interfaces 602 are for these otherradio access technologies (RAT). In exemplary embodiments, combinationsof LTE L2/L3 processors 604 and other radio access technology L2/L3processors 604 are included in radio access network interface 108C. Inexemplary embodiments, the radio access network interface 108Cprovides/distributes power to at least a first of the at least oneantenna unit 104.

In the forward path, each core network interface 602 receives downlinkphysical layer core network signals and converts the downlink physicallayer core network signals into downlink L2/L3 core network signals thatare communicated to a respective L2/L3 processor 604. In exemplaryembodiments, the purpose of the core network interface 602 is to convertthe data from the physical layer format used by the core network 622into a format acceptable to the RAT L2/L3 processor 604. In specificimplementations, at least one core network interface 602 receives IPcore network signals for LTE wireless signals from a core network 622,converts the IP core network signals into a format compatible with theLTE L2/L3 processor 604, such as packet data convergence protocol (PDCP)protocol data units (PDUs). In the reverse path, each core networkinterface 602 receives uplink wireless network information from theL2/L3 processor 604 and converts them into a format for communicationwith the respective core network 622. In specific implementations, atleast one core network interface 602 receives uplink L2/L3 data signals,such as PDCP PDUs and converts them into uplink physical layer IP corenetwork signals and communicates the core network signals to the atleast one additional component in the core network 622.

In the forward path, each L2/L3 processor 604 receives the L2/L3 RATsignals and converts them into downlink radio access technology (RAT)medium access control (MAC) layer protocol data units (PDUs) in theradio access technology (RAT) medium access control (MAC) layer, whereinthe radio access technology (RAT) medium access control layer usesrelevant bits more efficiently than the radio access technology (RAT)physical layer (such as I/Q modulated LTE samples or other I/Q modulatedsamples). In the reverse path, each L2/L3 processor 604 receives uplinkradio access technology (RAT) medium access control (MAC) layer protocoldata units (PDUs) in the radio access technology (RAT) medium accesscontrol (MAC) layer and converts the uplink RAT MAC PDUs in the RAT MAClayer into L2/L3 core network signals.

In the forward path, the transport MAC layer processor 606 converts thedownlink RAT MAC PDUs into downlink transport medium access control(MAC) layer protocol data units (PDUs) in a downlink transport mediumaccess control (MAC) layer for transport to the at least one remoteantenna unit 104 (such as through a distributed antenna system (DAS)).In the reverse path, the transport MAC layer processor 606 converts theuplink transport medium access control (MAC) layer protocol data units(PDUs) in an uplink transport medium access control (MAC) layer into theuplink radio access technology (RAT) medium access control (MAC) layerprotocol data units (PDUs). In exemplary embodiments, the transport MAClayer processor 606 also broadcasts signals to a plurality of differentremote antenna units 104. In exemplary embodiments, the transport MAClayer processor 606 also combines uplink DAS transport MAC layer PDUsfrom different antenna units 104 in an intelligent way.

In the forward path, the transport physical layer processor 608 convertsthe downlink transport MAC layer PDUs in the downlink transport MAClayer into downlink transport physical layer data streams in thetransport physical layer (such as an Ethernet physical layer or anotherDAS transport physical layer) and communicates the downlink transportphysical layer data streams across the at least one digitalcommunication medium 106 to the at least one antenna unit 104. In thereverse path, the transport physical layer processor 608 receives uplinktransport physical layer data streams in the transport physical layer(such as an Ethernet physical layer or another DAS transport physicallayer) from the at least one digital communication medium 106 andconverts the uplink transport physical layer data streams into uplinktransport MAC layer PDUs in the uplink transport MAC layer. In exemplaryembodiments, the transport physical layer processor 608 combines uplinktransport physical layer data streams from different antenna units 104in an intelligent way.

In exemplary embodiments, the radio access network interface clock unit610 generates a master reference clock and distributes the generatedmaster reference clock with the at least one remote antenna unit 104and/or other components within the distributed antenna system 100. Inexemplary embodiments, the radio access network interface clock unit 610communicates the master reference clock across a separate clock signallink 620. In other exemplary embodiments, the radio access networkinterface clock unit 610 communicates the master reference clock throughthe transport physical layer processor 608. In exemplary embodiments,the radio access network interface 108C receives a master referenceclock signal from at least one other component within the distributedantenna system 100, such as the at least one remote antenna unit 104 orfrom another external source, such as a source provided from the corenetwork 620. In exemplary embodiments, the master reference clock isderived from a core network signal received by the at least one corenetwork interface 602.

FIG. 7 is a flow diagram illustrating one exemplary embodiment of amethod 700 for efficiently transporting wireless network informationthrough a distributed antenna system. Exemplary method 700 begins atblock 702 with converting downlink wireless network information receivedfrom a radio access network interface from a first protocol layer to asecond protocol layer at a host unit in a distributed antenna system,wherein the second protocol layer uses relevant bits more efficientlythan the first protocol layer. Exemplary method 700 proceeds to block704 with communicating the downlink wireless network informationformatted in the second protocol layer from the host unit to at leastone antenna unit across at least one digital communication link.Exemplary method 700 proceeds to block 706 with converting the downlinkwireless network information communication form the host unit from thesecond protocol layer to downlink radio frequency signals at the atleast one antenna unit. Exemplary method 700 proceeds to block 708 withcommunicating the downlink radio frequency signals wirelessly using atleast one antenna at the at least one antenna unit.

FIG. 8 is a flow diagram illustrating one exemplary embodiment of amethod 800 for efficiently transporting wireless network informationthrough a distributed antenna system. Exemplary method 800 begins atblock 802 with receiving uplink radio frequency signals wirelessly at atleast one antenna unit using at least one antenna. Exemplary method 800proceeds to block 804 with converting uplink radio frequency signals touplink wireless network information in a second protocol layer at the atleast one antenna unit. Exemplary method 800 proceeds to block 806 withcommunicating the uplink wireless network information formatted in thesecond protocol layer from the at least one antenna unit to the hostunit across at least one digital communication link. Exemplary method800 proceeds to block 808 with converting the uplink wireless networkinformation received from the at least one antenna unit from the secondprotocol layer to a first protocol layer, wherein the second protocollayer uses relevant bits more efficiently than the first protocol layer.Exemplary method 800 proceeds to optional block 810 with combininguplink wireless network information received from a plurality of antennaunits into aggregate uplink wireless network information. In exemplaryembodiments, the uplink wireless network information is combined throughsummation (either digital or analog), weighted summation, averaging,multiplexing, etc.

FIG. 9 is a representation of an exemplary Layer 1 (L1)/Layer 2 (L2)protocol stack 900 for a radio access network (RAN) implementing LTE.The protocol stack 900 includes a packet data convergence protocol(PDCR) layer 902, a radio link control (RLC) layer 904, a medium accesscontrol (MAC) layer 906, and a physical (PHY) layer 908. In exemplaryembodiments, each of the packet data convergence protocol (PDCP) layer902, the radio link control (RLC) layer 904, and the medium accesscontrol (MAC) layer 906 are replaced with another type of Layer 2 (L2).In exemplary embodiments, the physical (PHY) layer 908 is replaced withanother type of Layer 1 (L1). In exemplary embodiments, at the top ofthe protocol stack 900 into the packet data convergence protocol layer902 comes IP packets from the radio access network (RAN) of the LTEsystem. In exemplary embodiments, the IP data then flows down throughthe radio link control layer 904 to the medium access control layer 906.In exemplary embodiments, going down through the various layers expandsthe data rate. In exemplary embodiments, there is only a slightexpansion down until the medium access control layer 904. Once the IPdata gets to the physical layer, a much larger expansion of the datarate occurs when going to the LTE physical layer 908.

In exemplary embodiments, the interface between the medium accesscontrol layer 904 and the LTE physical layer 908 is a clean interfacewhere processing in layers above are performed by one processing devicewhile processing lasers below are performed by another processingdevice. In exemplary embodiments, a processor (such as an ARM processor)performs the medium access control (MAC) layer 906 processing and theradio link control (RLC) layer 904 processing. In exemplary embodiments,a digital signal processor (DSP) performs the physical (PHY) layer 908processing. In other embodiments, a System on a Chip (SoC) performsprocessing for the medium access control (MAC) layer 906, the radio linkcontrol (RLC) layer 904, and the physical (PHY) layer 908. In otherexemplary embodiments, a field programmable gate array (FPGA) performsall or part of the processing for the medium access control (MAC) layer906, radio link control (RLC) layer 904, and/or the physical (PHY) layer908. In exemplary embodiments, the medium access control (MAC) protocoldata units (PDUs) at the medium access control (MAC) layer 906 aretransported through the distributed antenna system (such as adistributed antenna system 100) instead of I/Q baseband samples (at theLTE physical layer 908) because the medium access control (MAC) protocoldata units (PDUs) can be more efficiently transported than the I/Qbaseband samples.

FIGS. 10A-10B are block diagrams showing interaction in an exemplarysystem 1000 of various levels of a protocol stack, such as protocolstack 900. Each of FIGS. 10A-10B illustrates a different embodiment of asystem 1000, labeled 1000A-1000B respectively.

FIG. 10A is a block diagram of interaction in an exemplary system 1000Aof various levels of a protocol stack, such as protocol stack 900. Theexemplary system 1000A includes a radio access network interface 1010A(such as a baseband unit (BBU) implemented as an eNodeB with an IPEthernet connection to a core network or other type of baseband unit(BBU)), a host unit 1030, an antenna unit 1050 connected to the hostunit 1030 across a communication link 1040, and a subscriber unit 1070.In exemplary embodiments, the radio access network interface 1010Aincludes a core network Layer 2 (L2) 1012, a core network physical (PHY)layer 1014, a radio access technology (RAT) packet data convergenceprotocol (PDCP) layer 1016, a radio access technology (RAT) radio linkcontrol (RLC) layer 1018, a radio access technology (RAT) medium accesscontrol (MAC) layer 1020, and a radio access technology (RAT) physical(PHY) layer 1022. In exemplary embodiments, the core network Layer 2(L2) 1012 is an LTE core network Layer 2. In exemplary embodiments, thecore network physical (PHY) layer 1014 is replaced with another type ofcore network Layer 1 (L1). In exemplary embodiments, the core networkphysical (PHY) layer 1014 is an LTE core network physical layer. Inexemplary embodiments, each of the radio access technology (RAT) packetdata convergence protocol (PDCP) layer 1016, the radio access technology(RAT) radio link control (RLC) layer 1018, and the radio accesstechnology (RAT) medium access control (MAC) layer 1020 are replacedwith another type of radio access technology (RAT) Layer 2 (L2). Inexemplary embodiments, the radio access technology (RAT) packet dataconvergence protocol (PDCP) layer 1016 is an LTE packet data convergenceprotocol (PDCP) layer. In exemplary embodiments, the radio accesstechnology (RAT) radio link control (RLC) layer 1018 is an LTE RLClayer. In exemplary embodiments, the radio access technology (RAT)physical (PHY) layer 1022 is replaced with another type of radio accesstechnology (RAT) Layer 1 (L1).

In exemplary embodiments, the host unit 1030 includes a transport mediumaccess control (MAC) layer 1032, a radio access technology (RAT)physical (PHY) layer 1034, and a transport physical (PHY) layer 1036. Inexemplary embodiments the transport medium access control (MAC) layer1032 is replaced with another type of transport Layer 2 (L2). Inexemplary embodiments, the radio access technology (RAT) physical (PHY)layer 1034 is replaced with another type of radio access technology(RAT) Layer 1 (L1). In exemplary embodiments, the radio accesstechnology (RAT) physical (PHY) layer 1034 is an LTE physical (PHY)layer. In exemplary embodiments, the transport physical (PHY) layer 1036is replaced with another type of transport Layer 1 (L1). In exemplaryembodiments, the antenna unit 1050 includes a transport medium accesscontrol (MAC) layer 1052, a radio access technology (RAT) physical (PHY)layer 1054, and a transport physical (PHY) layer 1056. In exemplaryembodiments, the transport medium access control (MAC) layer 1052 is atransport Layer 2 (L2). In exemplary embodiments, the radio accesstechnology (RAT) physical (PHY) layer 1054 is a radio access technology(RAT) Layer 1 (L1). In exemplary embodiments, the radio accesstechnology (RAT) physical (PHY) layer 1054 is an LTE physical (PHY)layer. In exemplary embodiments, the transport physical (PHY) layer 1056is a transport Layer 1 (L1). In exemplary embodiments, the subscriberunit 1070 includes a radio access technology (RAT) packet dataconvergence protocol (PDCP) layer 1072, a radio access technology (RAT)radio link control (RLC) layer 1074, a radio access technology (RAT)medium access control (MAC) layer 1076, and a radio access technology(RAT) physical (PHY) layer 1078. In exemplary embodiments, each of theradio access technology (RAT) packet data convergence protocol (PDCP)layer 1072, the radio access technology (RAT) radio link control (RLC)layer 1074, and the radio access technology (RAT) medium access control(MAC) layer 1076 is replaced with another type of radio accesstechnology (RAT) Layer 2. In exemplary embodiments, each of the radioaccess technology (RAT) packet data convergence protocol (PDCP) layer1072, the radio access technology (RAT) radio link control (RLC) layer1074, and the radio access technology (RAT) medium access control (MAC)layer 1076 are LTE Layer 2 protocol layers. In exemplary embodiments,the radio access technology (RAT) physical (PHY) layer 1078 is replacedwith another type of radio access technology (RAT) Layer 1. In exemplaryembodiments, the radio access technology (RAT) physical (PHY) layer 1078is an LTE Layer 1 protocol layer.

In exemplary embodiments, the RAT physical (PHY) layer 1034 of the hostunit 1030 is communicatively coupled to the RAT physical (PHY) layer1022 of the radio access network interface 1010A. In exemplaryembodiments, the transport physical (PHY) layer 1056 of the antenna unit1050 is communicatively coupled to the transport physical (PHY) layer1036 of the host unit 1030 by the communication link 1040. In exemplaryembodiments, the radio access technology (RAT) physical (PHY) layer 1054of the antenna unit 1050 is coupled to an antenna 1060. In exemplaryembodiments, the radio access technology (RAT) physical (PHY) layer 1078of the subscriber unit is communicatively coupled to an antenna 1080. Inexemplary embodiments, the RAT physical (PHY) layer 1054 communicateswith the RAT physical (PHY) layer 1078 across a wireless link betweenantenna 1060 and antenna 1080.

In exemplary embodiments, the core network physical (PHY) layer 1014receives core network physical (PHY) layer protocol data units (PDUs)(such as a serial data stream) from a component in a core network (suchas core network 622 described above with reference to FIG. 6) andconverts the core network physical layer PDUs into core network Layer 2(L2) protocol data units (PDUs). In exemplary embodiments, the corenetwork Layer 2 (L2) 1012 converts the core network L2 PDUs into Layer 3(L3) protocol data units (PDUs) that are passed to the radio accesstechnology (RAT) packet data convergence protocol (PDCP) layer 1016. Inexemplary embodiments, the L3 PDUs are Internet Protocol (IP) PDUs. Inexemplary embodiments, the RAT PDCP layer 1016 converts the L3 PDUs toradio access technology (RAT) L2 PDUs that are further processed by theRAT radio link control (RLC) layer 1018 and the RAT medium accesscontrol (MAC) layer 1020. The RAT physical (PHY) layer 1022 converts theRAT L2 PDUs (such as RAT MAC PDUs) into radio access technology (RAT)physical layer data and communicates the RAT physical layer data (whichis LTE physical layer data in some embodiments, such as I/Q data) to theRAT physical (PHY) layer 1034 of the host unit 1030.

In exemplary embodiments, the host unit 1030 receives radio accesstechnology (RAT) physical layer data (such as LTE physical layer data)at the RAT physical (PHY) layer 1034 from the RAT physical (PHY) layer1022 of the radio access network interface 1010A. In exemplaryembodiments, the RAT physical layer data is analog RF or CPRI basebanddata. In exemplary embodiments, this RAT physical layer data is the datathat will be transmitted over the air interface between antennas 1060and antennas 1080. In exemplary embodiments, the host unit 1030 receivesthe physical layer data from the RAT physical (PHY) layer 1034 througheither a digital interface or an analog RF interface. In exemplaryembodiments, the RAT physical (PHY) layer 1034 of the host unit 1030undoes the RAT physical layer processing performed by the radio accessnetwork interface 1010A and extracts just the radio access technology(RAT) medium access control (MAC) protocol data units (PDUs) in the RATMAC layer and passes the RAT MAC PDUs (such as LTE MAC PDUs) to the RATmedium access control (MAC) layer 1032. In exemplary embodiments, theRAT MAC PDUs are translated into transport medium access control (MAC)layer protocol data units (PDUs) by the transport medium access control(MAC) layer 1032, such as DAS MAC PDUs. These transport MAC PDUs aresent over the communication link 1040 by the transport physical (PHY)layer 1036 (such as an Ethernet PHY or other DAS physical (PHY)processor) as synchronous serial data streams. In exemplary embodiments,packet data may be used for transport across the communication link1040. In exemplary embodiments, synchronization bits, timing bits, etc.are inserted by the transport physical (PHY) layer 1036 creatingadditional overhead. In exemplary embodiments, the communication link1040 is a Category building cable (or some other lower bandwidth cable).

In exemplary embodiments, the serial stream of data is received at thetransport physical (PHY) layer 1056 from the communication link 1040. Inexemplary embodiments, the transport physical (PHY) layer 1056 is anEthernet PHY or some other DAS physical (PHY) layer. In exemplaryembodiments, the transport physical (PHY) layer of the antenna unit 1050extracts the transport medium access control (MAC) PDUs in the transportmedium access control (MAC) layer 1052, such as DAS transport MAC PDUs.The transport medium access control (MAC) layer 1052 synchronizes to thestream of received transport MAC PDUs and reframes the transport MACPDUs into the radio access technology (RAT) medium access control (MAC)protocol data units (PDUs) in the radio access technology (RAT) mediumaccess control (MAC) layer. These RAT MAC PDUs are run through the RATphysical (PHY) layer 1054 resulting in a signal that is formatted in thesame way as the radio access technology (RAT) physical layer data (suchas LTE physical layer data) output from the RAT physical (PHY) layer1022 of the radio access network interface 1010A. In exemplaryembodiments, the RAT physical layer data is output via the RAT physical(PHY) layer 1054 and the antenna 1060 across the wireless link to theantenna 1080 of the physical (PHY) layer 1078 of the subscriber unit1070. By transporting across the communication link 1040 using thetransport MAC PDUs through the transport physical (PHY), the data rateof the signals over the communication link 1040 is reduced.

In the uplink the antenna unit 1050 receives signals at the RAT physical(PHY) layer 1054 via the antenna 1060 from the subscriber unit 1070,just as the radio access network interface 1010A could. The RAT physical(PHY) layer 1054 of the antenna unit 1050 processes these uplink signalsinto uplink RAT MAC PDUs in the RAT MAC layer. The RAT MAC PDUs aretranslated into the transport MAC PDUs by the transport MAC layer 1052.The transport MAC PDUs are converted by the transport physical (PHY)layer 1056 and sent over the communication link 1040 to the transportphysical (PHY) layer 1036 of the host unit 1030. In the host unit 1030,the detected transport data streams are gathered from the antenna units104 by the transport physical (PHY) layer 1036 (instead of I/Q RATsamples) and are converted to uplink transport MAC PDUs by the transportphysical (PHY) layer 1036. The uplink transport MAC PDUs are translatedinto uplink RAT MAC PDUs by the transport MAC layer 1032.

In exemplary embodiments, the uplink data from the antenna units 1050 iscombined in the host unit 1030. In exemplary embodiments, the uplinktransport MAC PDUs received from antenna units 1050 are intelligentlycombined using majority logic, soft weighted combining, averaging orother combining methods by the transport MAC layer 1032. The combinedMAC PDU is then translated into uplink RAT MAC PDUs by the transport MAClayer 1032. In exemplary embodiments, the uplink combining is performedin the transport physical layer 1036. In exemplary embodiments, theuplink combining is performed on the RAT MAC PDUs in the transport MAClayer 1032. The uplink RAT MAC PDUs are communicated as RAT physicallayer data by the RAT PHY layer 1034 to the RAT physical (PHY) layer1022 of the radio access network interface 1010A by the RAT physical(PHY) layer 1034 of the antenna unit 1050. In exemplary embodiments, theRAT PHY layer 1022 of the radio access network interface 1010A convertsthe RAT physical layer data into uplink RAT MAC PDUs that are passed tothe RAT MAC layer 1020 and up through RAT RLC layer 1018 and RAT PDCPlayer 1016 and converted into L3 PDUs that are communicated to the corenetwork Layer 2 (L2) 1012 down the core network stack and converted intocore network physical data and communicated by the core network physicallayer 1014 to the upstream core network component.

FIG. 10B is a block diagram of interaction in an exemplary system 1000Bof various levels of a protocol stack, such as protocol stack 900. Theexemplary system 1000B includes a radio access network interface 1010B(such as a baseband unit (BBU) implemented as an eNodeB with an IPEthernet connection to a core network or other type of baseband unit(BBU)), an antenna unit 1050 connected to the radio access networkinterface 1010B across a communication link 1040, and a subscriber unit1070. In exemplary embodiments, the radio access network interface 1010Bincludes a core network Layer 2 (L2) 1012, a core network physical (PHY)layer 1014, a radio access technology (RAT) packet data convergenceprotocol (PDCP) layer 1016, a radio access technology (RAT) radio linkcontrol (RLC) layer 1018, a radio access technology (RAT) medium accesscontrol (MAC) layer 1020, a transport medium access control (MAC) layer1102, and a transport physical (PHY) layer 1104. In exemplaryembodiments, the core network Layer 2 (L2) 1012 is an LTE core networkLayer 2 (L2). In exemplary embodiments, the core network physical (PHY)layer 1014 is replaced with another type of core network Layer 1 (L1).In exemplary embodiments, the core network physical layer 1012 is an LTEcore network physical layer. In exemplary embodiments, each of the radioaccess technology (RAT) packet data convergence protocol (PDCP) layer1016, the radio access technology (RAT) radio link control (RLC) layer1018, and the radio access technology (RAT) medium access control (MAC)layer 1020 is replaced with another type of radio access technology(RAT) Layer 2 (L2). In exemplary embodiments, the radio accesstechnology (RAT) packet data convergence protocol (PDCP) layer 1016 isan LTE packet data convergence protocol (PDCP) layer. In exemplaryembodiments, the radio access technology (RAT) radio link control (RLC)layer 1018 is an LTE radio link control (RLC) layer. In exemplaryembodiments, the radio access technology (RAT) medium access control(MAC) layer 1020 is an LTE medium access control (MAC) layer. Inexemplary embodiments, the transport medium access control (MAC) 1102 isreplaced with another type of transport Layer 2 (L2). In exemplaryembodiments, the transport physical (PHY) layer 1104 is replaced withanother type of transport Layer 1 (L1).

In exemplary embodiments, the antenna unit 1050 includes a transportmedium access control (MAC) layer 1052, a radio access technology (RAT)physical (PHY) layer 1054, and a transport physical (PHY) layer 1056. Inexemplary embodiments, the transport medium access control (MAC) layer1052 is replaced with another type of transport Layer 2 (L2). Inexemplary embodiments, the radio access technology (RAT) physical (PHY)layer 1054 is replaced with another type of radio access technology(RAT) Layer 1 (L1). In exemplary embodiments, the radio accesstechnology (RAT) physical (PHY) layer 1054 is an LTE physical (PHY)layer. In exemplary embodiments, the transport physical (PHY) layer 1056is replaced with another type of transport Layer 1 (L1). In exemplaryembodiments, the subscriber unit 1070 includes a radio access technology(RAT) packet data convergence protocol (PDCP) layer 1072, a radio accesstechnology (RAT) radio link control (RLC) layer 1074, a radio accesstechnology (RAT) medium access control (MAC) layer 1076, and a radioaccess technology (RAT) physical (PHY) layer 1078. In exemplaryembodiments, each of the radio access technology (RAT) packet dataconvergence protocol (PDCP) layer 1072, the radio access technology(RAT) radio link control (RLC) layer 1074, and the radio accesstechnology (RAT) medium access control (MAC) layer 1076 is replaced withanother type of radio access technology (RAT) Layer 2. In exemplaryembodiments, each of the radio access technology (RAT) packet dataconvergence protocol (PDCP) layer 1072, the radio access technology(RAT) radio link control (RLC) layer 1074, and the radio accesstechnology (RAT) medium access control (MAC) layer 1076 are LTE Layer 2protocol layers. In exemplary embodiments, the radio access technology(RAT) physical (PHY) layer 1078 is replaced with another type of radioaccess technology (RAT) Layer 1. In exemplary embodiments, the radioaccess technology (RAT) physical (PHY) layer 1078 is an LTE Layer 1protocol layer.

Distributed antenna system 1000B includes similar components todistributed antenna system 1000A and operates according to similarprinciples and methods as distributed antenna system 1000A describedabove. The difference between distributed antenna system 1000B anddistributed antenna system 1000A is that distributed antenna system1000B does not include the host unit 1030 and the radio access networkinterface 1010B includes transport medium access control (MAC) layer1102 in addition to RAT medium access control (MAC) layer 1020 andtransport physical (PHY) layer 1104 instead of RAT physical (PHY) layer1022. The transport medium access control (MAC) layer 1102 and transportphysical (PHY) layer 1104 enables the radio access network interface1010B to communicate directly with antenna unit 1050 using the transportMAC PDUs.

In exemplary embodiments in the downlink, the core network Layer (L2)1012, the core network physical layer 1014, the RAT PDCP layer 1016, theRAT RLC layer 1018, and the RAT medium access control (MAC) layer 1020function as described above with reference to the radio access networkinterface 1010A of FIG. 10A. The difference in the radio access networkinterface 1010B being that the transport medium access control (MAC)layer 1102 converts from radio access technology (RAT) medium accesscontrol (MAC) PDUs to transport medium access control (MAC) PDUs. Inexemplary embodiments, the transport physical (PHY) layer 1104 isimplemented using Ethernet PHY devices through which the transportmedium access control (MAC) PDUs are communicated across thecommunication link 1040. These transport MAC PDUs are sent over thecommunication link 1040 by the transport physical (PHY) layer 1104 (suchas an Ethernet PHY or other DAS physical (PHY) layer) as synchronousserial data streams. In exemplary embodiments, packet data may be usedfor transport across the communication link 1040. In exemplaryembodiments, synchronization bits, timing bits, etc. are inserted by thetransport physical (PHY) layer 1036 creating additional overhead. Inexemplary embodiments, the communication link 1040 is a Categorybuilding cable (or some other lower bandwidth cable).

In exemplary embodiments, the serial stream of data is received at thetransport physical (PHY) layer 1058 from the communication link 1040. Inexemplary embodiments, the transport physical (PHY) layer 1058 isimplemented using Ethernet PHY devices or some other DAS physical (PHY)layer. In exemplary embodiments, the transport physical (PHY) layer ofthe antenna unit 1050 extracts the transport medium access control (MAC)PDUs in the transport medium access control (MAC) layer 1054, such asDAS transport MAC PDUs. The transport medium access control (MAC) layer1054 synchronizes to the stream of received transport MAC PDUs andreframes the transport MAC PDUs into the radio access technology (RAT)medium access control (MAC) protocol data units (PDUs) in the radioaccess technology (RAT) medium access control (MAC) layer. These RAT MACPDUs are run through the RAT physical (PHY) layer 1056 resulting in asignal that is formatted in the same way as the radio access technology(RAT) physical layer data (such as LTE physical layer data) output fromthe RAT physical (PHY) layer 1022 of the radio access network interface1010A. In exemplary embodiments, the RAT physical layer data is outputvia the RAT physical (PHY) layer 1056 and the antenna 1060 across thewireless link to the antenna 1080 of the physical (PHY) layer 1078 ofthe subscriber unit 1070. By transporting across the communication link1040 using the transport MAC PDUs through the transport physical (PHY)layer, the data rate of the signals transported over the communicationlink 1040 is reduced.

In the uplink the antenna unit 1050 receives signals at the RAT physical(PHY) layer 1056 via the antenna 1060 from the subscriber unit 1070,just as the radio access network interface 1010A could. The RAT physical(PHY) layer 1056 of the antenna unit 1050 processes these uplink signalsinto uplink RAT MAC PDUs in the RAT MAC layer. The RAT MAC PDUs aretranslated into the transport MAC PDUs by the transport MAC layer 1054.The transport MAC PDUs are converted by the transport physical (PHY)layer 1058 and sent over the communication link 1040 to the transportphysical (PHY) 1104 of the radio access network interface 1010B. In theradio access network interface 1010B, the detected transport datastreams are gathered from the antenna units 1050 by the transportphysical (PHY) 1104 (instead of I/Q RAT samples) and are converted touplink transport MAC PDUs by the transport physical (PHY) layer 1104.The uplink transport MAC PDUs are translated into uplink RAT MAC PDUs bythe transport MAC layer 1102 and communicated to the RAT medium accesscontrol (MAC) 1020 of the radio access network interface 1010B. In theradio access network interface 1010B, the information is communicated upthe RAT/transport side of the protocol stack in the radio access networkinterface 1010B and down the core network side of the protocol stack1010B as described above with reference to radio access networkinterface 1010A.

In exemplary embodiments, the uplink data from the antenna units 1050 iscombined in the radio access network interface 1010B. In exemplaryembodiments the uplink transport MAC PDUs received from antenna units1050 are intelligently combined using majority logic, soft weightedcombining, averaging or other combining methods by the transport MAClayer 1102. The combined MAC PDU is then translated into uplink RAT MACPDUs by the transport MAC layer 1102. In exemplary embodiments theuplink combining is performed in the transport physical layer 1104. Inexemplary embodiments the uplink combining is performed on the RAT MACPDUs in the transport MAC layer 1102.

In exemplary embodiments, any of the processors described above mayinclude or function with software programs, firmware or other computerreadable instructions for carrying out various methods, process tasks,calculations, and control functions, used in the digital processingfunctionality described herein. These instructions are typically storedon any appropriate computer readable medium used for storage of computerreadable instructions or data structures. The computer readable mediumcan be implemented as any available media that can be accessed by ageneral purpose processor (GPP) or special purpose computer or processor(such as a field-programmable gate array (FPGA), application-specificintegrated circuit (ASIC) or other integrated circuit), or anyprogrammable logic device. Suitable processor-readable media may includestorage or memory media such as magnetic or optical media. For example,storage or memory media may include conventional hard disks, CompactDisk—Read Only Memory (CD-ROM), volatile or non-volatile media such asRandom Access Memory (RAM) (including, but not limited to, SynchronousDynamic Random Access Memory (SDRAM), Double Data Rate (DDR) RAM,RAIVIBUS Dynamic RAM (RDRAM), Static RAM (SRAM), etc.), Read Only Memory(ROM), Electrically Erasable Programmable ROM (EEPROM), and flashmemory, etc. Suitable processor-readable media may also includetransmission media such as electrical, electromagnetic, or digitalsignals, conveyed via a communication medium such as a network and/or awireless link.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiments shown. Therefore, it ismanifestly intended that this invention be limited only by the claimsand the equivalents thereof.

Example Embodiments

Example 1 includes an antenna unit comprising: a transport Layer 1processor configured to receive a downlink transport Layer 1 data streamfrom an upstream device and to convert the downlink transport Layer 1data stream into downlink transport Layer 2 protocol data units in adownlink transport Layer 2; a Layer 2 processor configured to convertthe downlink transport Layer 2 protocol data units in the downlinktransport Layer 2 into downlink radio access technology Layer 2 protocoldata units in a radio access technology Layer 2; a radio accesstechnology Layer 1 processor configured to generate a downlink radioaccess technology Layer 1 signal from the downlink radio accesstechnology Layer 2 protocol data units in the radio access technologyLayer 2; and a radio frequency conversion module configured to convertthe downlink radio access technology Layer 1 signal into radio frequencysignals for communication using an antenna.

Example 2 includes the antenna unit of Example 1, wherein the upstreamdevice is at least one of a radio access network interface and abaseband unit.

Example 3 includes the antenna unit of any of Examples 1-2, wherein theupstream device is a host unit in a distributed antenna system.

Example 4 includes the antenna unit of any of Examples 1-3, wherein theantenna is at least one of coupled to the antenna unit and integratedinto the antenna unit.

Example 5 includes the antenna unit of any of Examples 1-4, wherein theLayer 2 processor is a medium access control layer processor; andwherein the transport Layer 1 processor is a physical layer processor.

Example 6 includes the antenna unit of any of Examples 1-5, wherein theradio access technology Layer 1 is a Long Term Evolution physical layer;and wherein the radio access technology Layer 2 is a Long Term Evolutionmedium access control layer.

Example 7 includes an antenna unit comprising: a radio frequencyconversion module configured to convert radio frequency signals receivedusing an antenna into a Layer 1 uplink radio access technology signal; aradio access technology Layer 1 processor configured to generate uplinkradio access technology Layer 2 protocol data units in a radio accesstechnology Layer 2 from the Layer 1 uplink radio access technologysignal; a Layer 2 processor configured to convert the uplink radioaccess technology Layer 2 protocol data units in a radio accesstechnology Layer 2 into uplink transport Layer 2 protocol data units inthe uplink transport Layer 2; and a transport Layer 1 processorconfigured to convert uplink transport Layer 2 protocol data units in anuplink transport Layer 2 into an uplink transport Layer 1 data streamand to communicate the uplink transport Layer 1 data stream to anupstream device.

Example 8 includes the antenna unit of Example 7, wherein the upstreamdevice is at least one of a radio access network interface and abaseband unit.

Example 9 includes the antenna unit of any of Examples 7-8, wherein theupstream device is a host unit in a distributed antenna system.

Example 10 includes the antenna unit of any of Examples 7-9, wherein theantenna is at least one of coupled to the remote antenna unit andintegrated into the remote antenna unit.

Example 11 includes the antenna unit of any of Examples 7-10, whereinthe Layer 2 processor is a medium access control layer processor; andwherein the transport Layer 1 processor is a physical layer processor.

Example 12 includes the antenna unit of any of Examples 7-11, whereinthe radio access technology Layer 1 is a Long Term Evolution physicallayer; and wherein the radio access technology Layer 2 is a Long TermEvolution medium access control layer.

Example 13 includes a system comprising: a radio access networkinterface; at least one remote antenna unit communicatively coupled tothe radio access network interface across a first communication link;wherein the radio access network interface is configured to communicatea downlink transport Layer 1 data stream to the at least one remoteantenna unit across the first communication link; wherein the at leastone remote antenna unit is configured to: receive the downlink transportLayer 1 data stream from the radio access network interface; convert thedownlink transport Layer 1 data stream into downlink transport Layer 2protocol data units in a downlink transport Layer 2; convert thedownlink transport Layer 2 protocol data units in the downlink transportLayer 2 into downlink radio access technology Layer 2 protocol dataunits in a radio access technology Layer 2; generate a downlink radioaccess technology Layer 1 signal from the downlink radio accesstechnology Layer 2 protocol data units in the radio access technologyLayer 2; and convert the downlink radio access technology Layer 1 signalinto radio frequency signals for communication using an antenna.

Example 14 includes the system of Example 13, wherein the antenna is atleast one of coupled to the at least one remote antenna unit andintegrated into the at least one remote antenna unit.

Example 15 includes the system of any of Examples 13-14, wherein atleast a first digital communication link of the at least one digitalcommunication link is transported across a medium that is a Categorybuilding cabling.

Example 16 includes the system of any of Examples 13-15, wherein thedigital communication link is implemented using Ethernet physical layerdevices.

Example 17 includes the system of any of Examples 13-16, furthercomprising: a host unit communicatively coupled between the radio accessnetwork interface and the at least one antenna unit, the host unitconfigured to route the downlink wireless network information from theradio access network interface to the at least one remote antenna unit.

Example 18 includes a system comprising: a radio access networkinterface; at least one remote antenna unit communicatively coupled tothe radio access network interface across a first communication link;wherein the radio access network interface is configured to receive anuplink transport Layer 1 data stream from the at least one remoteantenna unit across the first communication link; wherein the at leastone remote antenna unit is configured to: convert radio frequencysignals received using an antenna into a Layer 1 uplink radio accesstechnology signal; generate uplink radio access technology Layer 2protocol data units in a radio access technology Layer 2 from the Layer1 uplink radio access technology signal; convert the uplink radio accesstechnology Layer 2 protocol data units in the radio access technologyLayer 2 into uplink transport Layer 2 protocol data units in the uplinktransport Layer 2; convert the uplink transport Layer 2 protocol dataunits in the uplink transport Layer 2 into an uplink transport Layer 1data stream; communicate the uplink transport Layer 1 data stream to theradio access network interface.

Example 19 includes the system of Example 18, wherein the antenna is atleast one of coupled to the at least one remote antenna unit andintegrated into the at least one remote antenna unit.

Example 20 includes the system of any of Examples 18-19, wherein atleast a first digital communication link of the at least one digitalcommunication link is transported across a medium that is a Categorybuilding cabling.

Example 21 includes the system of any of Examples 18-20, wherein thedigital communication link is implemented using Ethernet physical layerdevices.

Example 22 includes the system of any of Examples 18-21, wherein theradio access network interface is further configured to combine multipleuplink wireless network information received from a plurality of remoteantenna units including the at least one remote antenna unit.

Example 23 includes the system of any of Examples 18-22, furthercomprising: a host unit communicatively coupled between the radio accessnetwork interface and the at least one antenna unit, the host unitconfigured to combine multiple uplink wireless network informationreceived from a plurality of remote antenna units including the at leastone remote antenna unit.

Example 24 includes the system of Example 23, wherein the host unit isconfigured to combine the multiple uplink wireless network informationreceived from the plurality of antenna units using at least one ofmajority logic and weighted combining.

Example 25 includes the system of any of Examples 23-24, wherein thehost unit is configured to combine the multiple uplink wireless networkinformation received from the plurality of antenna units based onquality metrics received from the plurality of antenna units.

Example 26 includes a method for efficiently transporting wirelessnetwork information though a system, comprising: receiving a downlinktransport Layer 1 data stream from an upstream device at a remoteantenna unit; converting the downlink transport Layer 1 data stream intodownlink transport Layer 2 protocol data units in a downlink transportLayer 2 at the remote antenna unit; converting the downlink transportLayer 2 protocol data units in the downlink transport Layer 2 intodownlink radio access technology Layer 2 protocol data units in a radioaccess technology Layer 2 at the remote antenna unit; generating adownlink radio access technology Layer 1 signal from the downlink radioaccess technology Layer 2 protocol data units in the radio accesstechnology Layer 2 at the remote antenna unit; and converting thedownlink radio access technology Layer 1 signal into radio frequencysignals for communication using an antenna at the remote antenna unit.

Example 27 includes the method of Example 26, further comprising:wherein the upstream device is at least one of a radio access networkinterface and a baseband unit; and communicating the downlink transportLayer 1 data stream to the remote antenna unit from the at least one ofthe radio access network interface and the baseband unit.

Example 28 includes the method of any of Examples 26-27, whereinreceiving a downlink transport Layer 1 data stream from the upstreamdevice at the remote antenna unit occurs using Ethernet physical layerdevices.

Example 29 includes a method for efficiently transporting wirelessnetwork information through a system, comprising: converting radiofrequency signals received using an antenna at a remote antenna unitinto a uplink radio access technology Layer 1 signal at the remoteantenna unit; generating uplink radio access technology Layer 2 protocoldata units in a radio access technology Layer 2 from the uplink radioaccess technology Layer 1 signal at the remote antenna unit; convertingthe uplink radio access technology Layer 2 protocol data units in theradio access technology Layer 2 into uplink transport Layer 2 protocoldata units in an uplink transport Layer 2 at the remote antenna unit;converting the uplink transport Layer 2 protocol data units in theuplink transport Layer 2 into an uplink transport Layer 1 data stream atthe remote antenna unit; and communicating the uplink transport Layer 1data stream to an upstream device at the remote antenna unit.

Example 30 includes the method of Example 29, further comprising:wherein the upstream device is at least one of a radio access networkinterface and a baseband unit; and communicating the uplink transportLayer 1 data stream from the remote antenna unit to the at least one ofthe radio access network interface and the baseband unit.

Example 31 includes the method of any of Examples 29-30, whereincommunicating the uplink transport Layer 1 data stream to the upstreamdevice from the remote antenna unit occurs using Ethernet physical layerdevices.

What is claimed is:
 1. An antenna unit comprising: a first lower layerprocessor configured to receive a first lower layer signal from a deviceand to convert the first lower layer signal into first higher layer dataunits; a higher layer processor configured to convert the first higherlayer data units into second higher layer data units; a second lowerlayer processor configured to generate a second lower layer signal fromthe second higher layer data units; and a radio frequency conversionmodule configured to convert the second lower layer signal into radiofrequency signals for communication using an antenna; whereincommunication between the device and the antenna unit using the firstlower layer signal having the first higher layer data units has a lowerdata rate than would communication between the device and the antennaunit using the second lower layer signal having the second higher layerdata units.
 2. The antenna unit of claim 1, wherein the device is atleast one of a radio access network interface and a baseband unit. 3.The antenna unit of claim 1, wherein the device is a host unit in adistributed antenna system.
 4. The antenna unit of claim 1, wherein thesecond lower layer signal is a Long Term Evolution lower layer signal;and wherein the second higher layer data units are Long Term Evolutionmedium access control layer protocol data units.
 5. An antenna unitcomprising: a radio frequency conversion module configured to convertradio frequency signals received using an antenna into a first lowerlayer signal; a first lower layer processor configured to generate firsthigher layer data units from the first lower layer signal; a higherlayer processor configured to convert the first higher layer data unitsinto second higher layer data units; and a second lower layer processorconfigured to convert second higher layer data units into an transportdata stream and to communicate the transport data stream to a device;wherein communication between the antenna unit and the device using thetransport data stream having the second higher layer data units has alower data rate than would communication between the antenna unit andthe device using the first lower layer signal having the first higherlayer data units.
 6. The antenna unit of claim 5, wherein the device isat least one of a radio access network interface and a baseband unit. 7.The antenna unit of claim 5, wherein the device is a host unit in adistributed antenna system.
 8. The antenna unit of claim 5, wherein thefirst lower layer signal is a Long Term Evolution lower layer signal;and wherein the first higher layer data units are Long Term Evolutionmedium access control layer protocol data units.
 9. A system comprising:a radio access network interface; at least one remote antenna unitcommunicatively coupled to the radio access network interface across afirst communication link; wherein the radio access network interface isconfigured to communicate a first lower layer signal to the at least oneremote antenna unit across the first communication link; wherein the atleast one remote antenna unit is configured to: receive the first lowerlayer signal from the radio access network interface; convert the firstlower layer signal into first higher layer data units; convert the firsthigher layer data units into second higher layer data units; generate asecond lower layer signal from the second higher layer data units; andconvert the second lower layer signal into radio frequency signals forcommunication using an antenna; wherein communication between the radioaccess network interface and the at least one remote antenna unit usingthe first lower layer signal having the first higher layer data unitshas a lower data rate than would communication between the radio accessnetwork interface and the antenna unit using the second lower layersignal having the second higher layer data units.
 10. The system ofclaim 9, wherein the antenna is at least one of coupled to the at leastone remote antenna unit and integrated into the at least one remoteantenna unit.
 11. The system of claim 9, wherein at least a firstdigital communication link of the at least one digital communicationlink is transported across a medium that is a Category building cabling.12. The system of claim 9, wherein the digital communication link isimplemented using Ethernet physical layer devices.
 13. The system ofclaim 9, further comprising: a host unit communicatively coupled betweenthe radio access network interface and the at least one antenna unit,the host unit configured to route the first lower layer signal from theradio access network interface to the at least one remote antenna unit.14. A system comprising: a radio access network interface; at least oneremote antenna unit communicatively coupled to the radio access networkinterface across a first communication link; wherein the radio accessnetwork interface is configured to receive an transport data stream fromthe at least one remote antenna unit across the first communicationlink; wherein the at least one remote antenna unit is configured to:convert radio frequency signals received using an antenna into a firstlower layer signal; generate first higher layer data units from thefirst lower layer signal; convert the first higher layer data units intosecond higher layer data units; convert the second higher layer dataunits into an transport data stream; communicate the transport datastream to the radio access network interface; wherein communicationbetween the at least one remote antenna unit and the radio accessnetwork interface using the transport data stream having the secondhigher layer data units has a lower data rate than would communicationbetween the at least one remote antenna unit and the radio accessnetwork interface using the first lower layer signal having the firsthigher layer data units.
 15. The system of claim 14, wherein the antennais at least one of coupled to the at least one remote antenna unit andintegrated into the at least one remote antenna unit.
 16. The system ofclaim 14, wherein at least a first digital communication link of the atleast one digital communication link is transported across a medium thatis a Category building cabling.
 17. The system of claim 14, wherein thedigital communication link is implemented using Ethernet physical layerdevices.
 18. The system of claim 14, wherein the radio access networkinterface is further configured to combine multiple transport datastreams received from a plurality of remote antenna units including theat least one remote antenna unit.
 19. The system of claim 14, furthercomprising: a host unit communicatively coupled between the radio accessnetwork interface and the at least one antenna unit, the host unitconfigured to combine multiple transport data streams received from aplurality of remote antenna units including the at least one remoteantenna unit.
 20. The system of claim 19, wherein the host unit isconfigured to combine the multiple transport data streams received fromthe plurality of antenna units using at least one of majority logic andweighted combining.
 21. The system of claim 19, wherein the host unit isconfigured to combine the multiple transport data streams received fromthe plurality of antenna units based on quality metrics received fromthe plurality of antenna units.